CivArchive

    V5 OUT NOW:

    The new V5 model should improve many things about the model even tho there are still some problems that are hard to address. I tried to stop the models tendency for extreme jiggle and the characters always grabbing their breasts and I think I have mostly succeeded.
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    Generation Settings:
    I use it with speed up loras on 768x1024 for 81 frames with a strength of 0.7

    Prompting:

    • Trigger the lora with --> "Br3ast3xpansion, her breasts grow"

    • "Br3ast3xpansion, her breasts grow" should work for most users

    • If you want the character to grab their breasts like in V1 try --> "grabbing breasts"

    • The model is trained on the sizes --> "big breasts" "giant breasts"

    Tips:

    Choose a starting image that shows cleavage or parts of the breast so the models knows where to start. Otherwise the model has a tendency to often make the clothes semi transparent. This behaviour is the most extreme when creating anime style videos especially with white shirts.

    The model is not tested on t2v but since wan 2.2 is very capable this could work.

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    V1:
    A new Breast Expansion Model for Wan 2.2. This model should work on Realistic and Anime images but I prefer the anime ones. This is only the first prototype trained on a big collection of lower quality videos and I will try to improve on this one by training it on the better videos.

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    Special thanks to @CaptainWebSpinner for helping me out. He has made a Wan 2.1 Lora this was based on: https://civarchive.com/models/1528155/breast-expansion-wan-i2v

    Because I like people generating nice content Commercial and Non Commercial use is allowed but be so nice and say that you used my model.

    Description

    New V5 version should improve many issues like characters always grabbing breasts and extreme bouncing but it is not perfect.

    FAQ

    Comments (28)

    redsnailSep 11, 2025
    CivitAI

    How can you prevent them from jumping after transformation?

    VinPara
    Author
    Sep 11, 2025

    Sadly I know no way to stop it, it has been one of the main issues I had when training this model.

    ChahkSep 11, 2025
    CivitAI

    Is there a way to limit the size of how large the breasts expand?

    VinPara
    Author
    Sep 11, 2025· 1 reaction

    It is very hard to control, maybe using the model at a lower strength can help.

    herrboehmeSep 13, 2025· 3 reactions
    CivitAI

    Thank you so much for crafting this and conducting further research for improvement.

    VinPara
    Author
    Sep 13, 2025

    your welcome

    wol94Sep 13, 2025
    CivitAI
    Everything is good, but can't you make it bigger like the clothes so that the nipples aren't visible?

    VinPara
    Author
    Sep 14, 2025· 1 reaction

    Sadly I was not able to adress this problem during training even tho I tried. If you are doing an anime style you could try realistic or 3d styles, they are less effected. White shirts are most problematic, normally it helps to show more cleavage in the start image so the model knows where to begin the transformation.

    wol94Sep 14, 2025

    @VinPara okay ty! Will my breasts get bigger if I increase the intensity?

    VinPara
    Author
    Oct 3, 2025

    @wol94 could be, best if you just try out

    alachaise942Sep 18, 2025
    CivitAI

    What workflow do you recommend to run this Lora ?

    VinPara
    Author
    Oct 3, 2025

    any wan 2.2 i2v workflow should work

    twistedskyOct 11, 2025· 1 reaction
    CivitAI

    Awesome work! Now if someone could just make a booty expansion lora :')

    bryanarreola4630Oct 12, 2025
    CivitAI

    New to wan 2.2. do you need both high and low lora or which is needed?

    dokurochan16Oct 12, 2025
    CivitAI

    for some reason the face on my characters get removed as camera focuses only on the breasts is there a way to fix this?

    JolyBelleOct 16, 2025
    CivitAI

    I use K4_K_M, gguf. I just type trigger words in the prompt and that's it, Lora weight: high noise 1, low noise 1, but the result is just trash, not related to breast exp. Can you tell me what's wrong? Maybe I need a smaller weight?

    ZacharyTigerNov 12, 2025

    If you apply both at full strength, they’ll fight each other — one trying to freeze the frame, the other trying to explode it. Not simultaneously — you usually pick one, depending on your goal.
    But some advanced workflows blend both (for example, 0.6 strength Low + 0.3 strength High) to fine-tune the amount of motion energy you want.

    JolyBelleOct 16, 2025
    CivitAI

    I use K4_K_M, gguf. I just type trigger words in the prompt and that's it, Lora weight: high noise 1, low noise 1, but the result is just trash, not related to breast exp. Can you tell me what's wrong? Maybe I need a smaller weight?

    ComfyUserAiOct 29, 2025· 2 reactions
    CivitAI

    Is there a suggested prompt to make the boobs not bounce or make them not jump up and down or grab the boobs?

    Frozen_SparklesNov 12, 2025

    I feel your pain. For some reason "her breasts wobble while she settles herself down in her seat" translates into AI as: "she shakes her ass for the camera." Sigh...

    Devilday666Nov 2, 2025· 4 reactions
    CivitAI

    How about ass expansion next or busty expansion as a whole

    snickerdooodleNov 8, 2025
    CivitAI

    This is a really nicely done LoRa. I've had a lot of issues with breast expansion LoRas attempted before but this thing started producing good results pretty much immediately. For those getting results that are way too shaky, only put this in the high-noise slot. I had put it in low-noise out of habit as well but noticed my mistake pretty quickly after the jittery nature of the videos.

    SinglePageNov 10, 2025· 10 reactions
    CivitAI

    I really feel like I'm hitting the sweet spot with this lora...around 0.6H and 0.7L seem to do great. Nice work on this one! But if you ever would want to make a version for breasts that stay covered and strain against clothes, I'd use the hell out of it. :)

    bradh88845Jan 25, 2026
    CivitAI

    Im just starting out doing AI work. Do you by chance have a workflow template to run this?

    techmangreatFeb 14, 2026· 1 reaction
    CivitAI

    The big question is, where did he get the training data for this lora lol

    VinPara
    Author
    Mar 19, 2026· 3 reactions

    I created the training data by using AI generated Videos that I have done without it. It was extremely hard to generate them. Each iteration I picked the best ones so I slowly made the model understand what I want.

    This takes a long time and is also the reason for most of the issues like the slow mo fell and extreme bouncing. Because those small error tendencies got worse with each new version.

    void2258Feb 27, 2026
    CivitAI

    Can you control the sizing? As far as I can see, it always goes to the save very large size.

    LORA
    Wan Video 2.2 I2V-A14B

    Details

    Downloads
    6,821
    Platform
    CivitAI
    Platform Status
    Available
    Created
    9/11/2025
    Updated
    5/17/2026
    Deleted
    -
    Trigger Words:
    Br3ast3xpansion
    her breasts grow

    Files

    Available On (1 platform)

    Same model published on other platforms. May have additional downloads or version variants.