Guys; are your chances of approaching a girl automatically smaller if she's flat? (Chest and ass) What if she has one big and not the other?

I'd assume it's a guy and keep walking

No

Normal guys don't automatically approach them but womanizers do, because they assume flat girls have a low self-esteem, therefore an easy target.

Actually they tend to increase if she's small chested. I'm not really into bigger boobs.

No .. there are no bad breasts .. and it’s not all about that anyway
I would have no problem

NIL chance as I am on a very short leash

Na
Depends on the individual

Does not matter.

Guys approach a flat chested girl ? dont you think that's sick ?

If she has a cute face none of that matters... unless she has a big ass then he might think twice