Medium to large female breasts, traditionally of a size and/or shape configuration that encourage thoughts or acts of ejaculation upon them by male partners or suitors.
Show me those cum pumpkins baby, I wanna drop a fat load all over them!
Female breasts, specifically those large enough to accomplish ejaculation (the "jizz") through the act of tittyfucking (the "squeezing".
Check out the jizz squeezers on the chick in the red bikini! WOW!