when the bra your wearing makes your boobs look like they are pretty much on your shoulders.
that girl has some big shoulder boobs with that bra on.
The contact made between the shoulder of one person (usually male) and the boob of a female leaning over the shoulder of the other person.
Dude, I totally got some shoulder boob when that waitress delivered our food!
That comfortable spot on a guys chest under his shoulder and above his nipple. Where girls (or guys) usually put their head when cuddling with a guy.
Mmm, his shoulder boob is so soft and squishy, i'm going to fall asleep now.