The game forces male body type to look old and ugly, that's why I had to pick female body type.
The male body type looks like a ripped 30-something. If that's being old and ugly that means like 90% of dudes out there aren't good enough for you XD
I get the frustration of having to pick between only 2 boyd types tho. I personally find it disappointing that you have to pick a set body, and you can't change anything about it. That's a choice from the devs. It allows them to have more clothing options if they only have to make 2 models for each. And they don't have to work on a clothing deformation system that adjust to individual character settings. Was that the right choice to make though? I don't know. Folks care a lot about customizing their character, and I'd wager the playerbase would be happier with more options, even if it means their character would look wonky in some clothing items.
And to answer the initial question, apparently even if you pick a different breast size, the "female" clothing models will look the same on your character. They're counting on people not noticing that the titty slider does nothing once you put a shirt on. That would explain why there's no "OFF" setting for boobs.