on a slightly unrelated note, bigger boobs make it a lot harder to flash someone on an impulse. here's the theory, complete with hypothetical scenario)
let's say woman A wears a 38C, woman B wears a 34B. both want to put on a little peepshow. woman A has on a bigger bra which (better be) stronger to hold her up. woman B's bra is prolly easier to put on, lift up, etc. so she could quickly pull up her shirt and bra and readjust herself with little to no difficulty. woman A prolly isnt gonna be able to do all that with such swiftness.
this is all assumption, since i havent been anywhere near a 34B in ages, and even then, i wasnt (nor am i now) in the interest of flashing anyone.