How big is too big?

I have no idea but now you can figure it out yourself.
Another request this LyCORIS is trained on various 90s tittymonsters.

Disclaimer - Unless you're using NAI or a model with NAI mixed in and want to prompt 3D you probably don't want to use this, use one of the photorealistic models along with a suitable LoRA/LyCORIS (if needed).

How to use
Prompt away as usual, strong tags are "large breasts", "huge breasts" and "gigantic breasts". "Mature female" was also a common tag that should work well and this LyCORIS tend to output ladies in that age bracket unless told otherwise.
Influenced by the era and (fairly) low res images in the dataset the output often tends to get a touch of sepia or polaroid style. 90's hair also comes as a free bonus.
The results usually come out quite well, at least on AOM2, to the point I frequently didn't even bother using face restoration.
For more prompt tips see the sample images or the uploaded zip of training tags.

MISC
Dataset of 110 images trained at 768px on NAI.
All sample images are raw txt2img upscaled, no helper embeddings/negatives used. E.g. - things should look even better if you do.
The training was done on a small subset of images, as such the output of this LyCORIS is not an accurate representation neither in quality or style of the 90s. Go buy a time machine if you want the good stuff.