Before you start typing, hear me out:
When you're having sex, what do you feel ass you penetrate your girl? That's right, her cheeks clapping on your crotch area. It enhances the pleasure and resists the impact of your thrusts, which allows you to go all in. When you're not having sex, what hurts to have more? That's right, tits. They give you back pain and it gets worse the bigger they are while ass cheeks give you a free pillow to sit on.
And back to sex, specifically, lesbian sex. You know how they tease each others' nipples? That doesn't work with big tits, as they're less sensitive as small tits, so you're often better off having ass over tits.
And back to straight sex, what the fuck can you do if your girl isn't big up there? You can grope and tease her, but titfucks are not an option. There are other ways to tease a woman like neck kisses and stuff.
Now I like big tits, I love them, but I think it's rational to pick ass; So I was born a tits man, but I am an ass man by choice