After swallowing gizz from a b.j., wishing one hadn't done so. Usually because the cum flavor was nasty, almost made one choke, or there was nothing to wash away the aftertaste with or realizing that it may not have been a safe swallow due to not knowing much of the sexual history of the cum dumper.
One Girl to Another: I totally have Swallower's Remorse!!
Girl: I gave JP head last nite, but the flavor was just nasty! I mean he smokes cigarettes and guys who smoke have nastier gizz, but his was positively rancid! I gargled half a bottle of Listerine, but I swear I can still taste it!
Another: Maybe he hadn't jerked off in a while.
Girl: You might be right, he seemed really horned up and came quick. Well let's go do shots of Tequila, maybe that will wash it away.