Stepmother Effect is a sissification porn game with real pics and video, written by K17.
You play as a young man living under the same roof as your dominant stepmom - while battling a secret porn addiction. But she has plans of her own.
Multiple paths can lead to submission, transformation, or something even more daring. The question is... will you fight it, or embrace the change?
About this game
- Genre
- Adult Sandbox Game
- Developer
- K17
- Release date
- July 2022
- Updated
- July 2026 (version 2.6.9)
- Status
- Ongoing
- Game Engine
- Twine (play in your browser)
Updated on July 25th 2026, what's new in version 2.6.9?
Version 2.6.9a introduces a new main story centered on Mira, complete with three new endings, additional media, special dreams, and an unlockable outfit. The update also expands gameplay with a new backyard area, a gaming skill system (currently with no gameplay effect), a cheats button, UI improvements, and various bug fixes and optimizations. To improve stability, sidequests have been restricted so that only certain combinations can be active at the same time, reducing the chance of conflicts.
V 2.6.9a
- Added new main story with Mira (see note).
- Added 3 regular endings (One ending you can continue playing).
- Added new media.
- Added special dreams.
- Added unlockable outfit.
- Updated image for earrings 1.
- Added backyard.
- Added gaming skill (does nothing for now).
- When playing a game, the gaming skill increase by 1.
- Optimized some media files.
- Prevented that to many sidequests could be played at the same time (see note2).
- Updated the right sidebar menu.
- Added cheats button (bedroom).
- Fixed bug with some media possibly not working on Linux/Mac.
- Updated code for some older main stories.
- Updated credits (Added Tal A. Baskin).
- Added silver member in the credits; user#a67146ba
Note: To start the new story, when trying to remove the porn block, select "You clean your PC...".
Note2: To reduce the chance of conflict, only those sidequest can be play together:
Motel P1 & P2, Auto-closet, Emy P1 & P2, Pawnshop, and clinic. The others, only one at a time.
V 2.6.8
- Added main story with Sila (see note).
- Added 4 regular endings (New, one ending you can continue playing).
- Added new media.
- Added special dreams.
- Added unlockable outfit.
- Added 3 new anonymous phone messages (related to panties).
- Outside changes for evening and night.
- Optimized some media files.
- Updated Nadia's avatar.
- Fixed broken image link in Craig's story.
- Fixed missing unlock lingerie store in Craig's story.
- Fixed bug with old save in the strip club (when entering, giving a tip to a dancer).
- Fixed typos.
Note: To start the new story, when trying to remove the porn block, select "You want to upgrade your PC...".
V 2.6.7a
- Finished Veronica's main story (see note).
- In this main story, you can go outside only wearing your regular clothes.
- Added 3 regular endings.
- Added new media.
- Added special dreams.
- Added unlockable outfit.
- Updated the mirror (fingernails).
- Optimized some media files.
- Rewrite part of ending 85 (to brake up a long line).
- Fixed bug when returning to the menu choice that the player's name didn't return to the male one.
- Fixed bug with Lisa's story not giving skills.
- Fixed bug with mirror not showing the breast/butt implants from the clinic in Lisa/Rebeccas's stories.
- Fixed bug with the mirror and the skills for Kendra's story.
- Fixed bug with ball gag not being removed in Karen's dungeon.
- Fixed bug with mirror, not showing virginity lost in Karen's story.
- Fixed bug with missing skills in Karen's story.
- Fixed bug with skills not reverting to their previous values when doing a semi-loopback.
- Fixed bug with closet and outfit giving by Kendra when waking up.
- Fixed typos.
Note: To start the new story, when trying to remove the porn block, select "You receive an Email from your college...".
V 2.6.6a
- Added gamer main story (see note).
- Added 3 regular endings.
- Added new media.
- Added special dreams.
- Added unlockable outfit.
- Optimized some media files.
- Stepmom will collect 200 after being a webcam girl.
- Oral/anal skills are now working in stories like church, Alicia.
- Fixed bug of player's name hard coded in 2 places in the game.
- Fixed bug with stepmom's name hard coded in 1 place in the game.
- Fixed typos.
- Added gold member in the credits; user#228acb9
Note: To start the new story, when trying to remove the porn block, select "You decide to play a game...".
Version 2.6.5a
- Added basement main story (see note)
- In this story, you can only go outside wearing your regular clothes
- Added 3 regular endings
- Added new media
- Added special dreams
- Added unlockable outfit
- Added 2 new skills in the menu
👩⚕️ Updated Nikki’s avatar (clinic doctor)
🩱 Updated body suit image and added to the closet (Corset)
- Added missing hints in Freemode story
🐞 Fixed bug where reward was missing after completing all endings in stepmom’s story
Note:
To start the new story, when attempting to remove the porn block, select "Stepmom wants to talk to you".
🔥 Stepmother Effect – Version 2.6.4a
🆕 New Content
- Added Valerie's story (see note below).
- Added 3 regular endings.
- Added new media.
- Added special dreams.
- Added unlockable outfit.
- Added tongue piercing in closet menu.
- Added avatar for barista girl.
- Added avatar for the clinic receptionist.
- Added subquest hints for Farm's, Ada's and Nina's stories.
🔁 Story Expansions
- Added semi-loopback for SAM-Autocloset's story (Ending 30, 31, 32).
- Added semi-loopback for Alicia's story (Ending 36, 37, 38).
- Added semi-loopback for Crystal's story (Ending 39, 40, 41).
🎨 Updates & Improvements
- Updated avatar for Melanie (Marwalt seller).
- Updated Marwalt (You can interact with Mela at all time).
- Optimized some media files.
- Fixed many typos (Mainly in the SAM-Autocloset's story).
🛠 Fixes
- Fixed bug at museum of missing exit with Irene's story.
- Fixed the hints for SAM-Autocloset's story.
- Fixed the hints for Crystal's story.
- Fixed bug with dildo availability with some stories.
- Fixed bug with blonde wig 3, earring 1, and tongue piercing with old saves.
- Fixed bug with room 7 and missing exit.
- Fixed bug with passing time at Ada's house when she's not there.
📌 Note
To start the new story, when trying to remove the porn block, select "Scroll listings."
V 2.6.3
- Added Carmilla's story (see note).
- Added 2 regular endings.
- Added 1 subquest ending.
- Added new media.
- Added special dreams.
- Added unlockable outfit and accessories.
- Added new black wig3.
- Added avatar for the dark alley drunk.
- Added avatar for SofTeckk's receptionist.
- Added subquest hints for Nadia's, Ivy's, Ania's, church's, SofTeckk's, and Sarah's stories.
- Added semi-loopback for the therapist's story (Ending 17, 18).
- Added 4 new categories in outfit; ear, mouth, belt and corset (moved earrings, ball gag, belt and corsets to them).
- In closet, transferred nighties to the top section.
- In closet, renamed Headwear1 to Hat, and Headwear2 to Wig.
- In closet, the face category, renamed "removed mask & earrings" to "removed mask & glasses".
- Tongue piercing will appear in the mouth category in the outfit display.
- Mirror will mention if you are wearing any earrings.
- Optimized some media files.
- Reworked Auto closet's story (Stepmom) and improved the layout. Also hints were not needed.
- Fixed major bug at the museum when playing Diana's and Lara's and/or Irene's story at the same time.
- Fixed bug with red latex gloves in the wrong category in outfit.
- Fixed bug with earring 4 and the gold one conflicting in the mirror.
- Fixed bug with the femininity not being displayed with some old save (will set to 0).
- Fixed bug with the fitness not being displayed with some old save (will set to 0).
- Fixed bug with Wendy's story hints with old save.
- Fixed bug with Jenny's story hints with old save.
- Fixed bug with motel's story hints with old save.
- Fixed typos.
Note: To start the new story, go to the dark alley, then Velvet Fang store (opens in evening).
V 2.6.2
- Added Lucy's story (see note).
- Added 2 regular endings.
- Added 1 subquest ending.
- Added new media.
- Added special dreams.
- Added 2 unlockable outfits.
- Fitness is reduced when eating sweets.
- Added subquest hints for Diana's, motel's, Wendy's, Jenny's, sexshop's, Emy's, asylum's and Diamond's stories.
- Added semi-loopback for Karen's story (Ending 13, 14, 15).
- When doing a semi-loopback, previous femininity and fitness points are restored.
- Added drinking coffee (pass time) at Coffee shop.
- Added F95 site link on main menu.
- Transfered links from credits section to the main menu.
- Updated layout of the left menu.
- Optimized some media files.
- Reworked Karen's story and improved the layout.
- Fixed Jenny's story, time passes when going to the photo studio.
- Fixed bug with Nadia's training not increasing fitness.
- Fixed typos.
Note: To start the new story, go to the Bakery.
V 2.6.1a
- Added Irene's story (see note).
- Added 2 regular endings.
- Added 1 subquest ending.
- Added new media.
- Added special dreams.
- Added unlockable outfit.
- Added subquest hints for Irene's story.
- Added subquest hints for Lura's and Lara stories (other subquest story's hints will be added gradualy).
- Added semi loopback for Kendra's story (Ending 1, 3, 3a, 4).
- Added a right menu bar, and transferred the clothes to it.
- Added to the left menu bar; Quest's hint, Femininity, Fitness, Cleaning skill and grades points.
- Quest button renamed "Ends list".
- Ends list now contain links to each ending scene you unlocked.
- Merged ending 3a and 3b on ending list.
- Optimized some media files.
- Reworked Kendra's story and improved/fixed the layout.
- Fixed broken images in outfit menu.
- Fixed bug with pink chastity cage image broken with old save.
- Fixed bug with the money not being displayed with some old save (will reset to 150).
- Fixed broken images with Jenny and Lura stories, plus a few loose ones.
- Fixed bug with black garterbelt1 appearing at the panties location.
- Fixed bug with grades that don't reset when looping back.
- Fixed bug with motel room that cannot be cleaned during, and after, the lab story.
- Fixed bug in museum with Lara and Diana stories conflicting.
- Fixed typos.
Note: To start the new story, go to the museum, and select to see the exhibit.
V 2.6.0
- Added Wendy's story (see note).
- Added 2 regular endings.
- Added 1 subquest ending.
- Added 3 unlockable outfits.
- Added special dreams.
- Added new media.
- Optimized some media files.
- Added semi loopback for SAM's story (Ending 5 and 6, 7a and 7b).
- Fixed bug with a special dream (choices) in Ada's story not showing up with other stories.
- Fixed bug with mirror in FM, showing the same butt size for all 3 choices.
- Fixed bug in one scene of Lisa story fitting you the wrong cage/plug.
- Fixed bug with missing image for the nap.
- Fixed typos in motel's story.
Note: To start the new story, need ending S1 or S2 (testing the pills on someone), go back to room 3 (back of motel).
V 2.5.9
- Added Craig and Rebecca's main story(see note).
- Added 3 regular endings.
- Added 2 unlockable outfits.
- Added special dreams.
- Added new media.
- Mirror will show breasts size for this story.
- Unlock items in stores and add Femininity as this story progress.
- Updated Craig's avatar.
- Optimized some media files.
- Added semi loopback for Rebecca's story(Ending 11 and 12).
- Fixed typos in Rebecca's story.
- Fixed bug with missing media in Rebecca's story.
- Added platinum member in the credits; cantbearsed.
- Added silver member in the credits; Addi95, Faux1272.
Note: To start the new story, when you try to remove the porn block on your PC, select lie on your bed.
