>>11269918
The scenario can vary, my favorite is consensual non-consent - the boob growth is hated or not wanted, but is so damn satisfying sexually she cant help but become a tit-cow. A lust-takes over kind of thing. Bonus points if she gets chubbier as well and goes full breeder. Pic somewhat related - unfortunately don't know source.

I also love a fetish for growth or other strong motivating factor - wanting bigger tits for selfish reasons, only for it to backfire, growing past the point of controlling the situation. I love the concept of a cowgirl milk-edging her own udders only for them to get so full she cant milk herself, leading to incredible distress. I've experimented with bursting from there but while hot on the lead up the realistic gory result is not my thing. Trying to figure out an alternative between that and cartoon "oopsies everything is reset".

One of my favorite RP's is an adventuring cowgirl afflicted with a curse that causes her breasts to grow if she milks - combines both of the above into a changeable format. Of course milking feels sinfully good so she's constantly tempted to pleasure herself. Easy enough to make her hyper huge and then shrink her back down with plot bull-shittery so you can do it all over again.