>>73162342By themselves they are already stimulants. Just looking at them can entice and charm men. It's merely a reproductive skill.
But about the size there's no convoluted explanation. Larger and bigger breasts imply more lactation therefore, just like wider hips, the superior choice when it comes to breeding. There's also the fetishist angle but most of the time it's subconscious horny biology bullshit.
Anyways, it's just lizard brain shit. The same can happen with wide hips, big asses or thighs.