A surround pound is when you have sex with one person, then someone different and finish off the day by having sex with person number one once again in the same day.
I woke up this morning and had sex with my gf before heading off to work. Once I got to work, the ex GF wanted to have lunch at her place which meant a nooner. Once I got home from work, my gf called and came over where we had sex once more to round out a perfect surround pound for the day.
1. Pleasure-saturated intercourse, wherein the receiving buttocks, or badonkadonk, is so prodigious as to encompass the sender's anterior torso.
E.g. "Dude, I met this girl with such a fat ass. . . Total surround pound material."
"Found you Miss New Booty! Damn, shorty can get a surround pound."
"Look at that ass. . . ." "Yeah, she could probably give you a surround pound."