When a male ejaculates upon a squash (or similar produce i.e. cucumber, zucchini, large carrot sticks) then proceeds to insert jizz covered veggie into a woman's (or male) orifice of choice.
"I was Squashpumping Megan the other day; You should have seen the load I blew on that zucchini, dawg."
"I hope Julia doesn't choke on all of our cum when we start Squashpumping her"
"Wanna have a Squashpumping orgy?"