You just have to automatically assume anything dealing with breasts is a sexual topic, don't you? What is your problem with realistic physics?
Anything dealing with breasts automatically IS a sexual topic. You can't say "make boobs jiggle with realistic physics" with a straight face.

No one is talking about jiggly physics as some sexual fetish. Realism =! Sexism.
In this case, realisim = sexualisim. The only reason to make boobs jiggle is sexual innuendo. I've yet to see a single game actually have "realistic" boob physics anyway. It's always ridiculously exaggerated. In real life boobs don't jiggle the way they do in most games with allegedly realistic physics.

If you ask me, if you've looked at the breasts of characters in game long enough to notice that they don't have jiggle physics, then you've been spending too much time looking at the breasts and not enough time looking at the rest of the character.