A girlfriend

Frank looked over his shoulder to see a pretty brunette looking on, her face a blend of amusement and shock.

"Who the fuck are you?" he growled, continuing to thrust into the trembling, protesting blonde who seemed oblivious to the new arrival.

"The bitch you're railing? That's my girlfriend, that's who I am. Mary Lou what the fuck are you doing?"

"I guess she goes both ways," Frank laughed, fondling the blonde and continuing to fuck her. "How about you?"

"Strictly a girl's girl champ. Sorry. If you had a threesome planned, you can count me out. Hey Mary Lou! You almost done?"

"She's come a buncha times," Frank growled. "I fucked her brains out."

"OH FUCK! OH FUCK YEAAAAAAAAAHH!" Mary Lou howled as she climaxed fiercely, bucking wildly on Frank's impaling cock, then slumping forward, gasping and panting, her cunt milking his cock with the aftershocks of her orgasm.

"I think she's done now," Frank laughed, pulling out of her and standing up. "She's a pretty good fuck for a dyke."

"Cass!" the blonde squealed, noticing the newcomer for the first time. "I...uhh...he forced me...made me..."

"They always do, according to you," Cass said shaking her head before turning to Frank. "I'll take over here pal. Too bad you didn't come, but there's no shortage of bitches at this party that'll be more than happy to take your load."

"No hard feelings?" he grinned as the brunette started to pet Mary Lou, who whimpered and purred under her touch.

"None at all. Mary Lou needs a cock now and then. And likes to pretend she's being forced. But she's just a little slut at heart, aren't you? That's my good little bitch." The two of them slid into a passionate embrace, ignoring Frank as he dressed. They slid to the floor, Cass expertly stripping her bikini off before pulling Mary Lou to her, the two of them wrapped together in a moaning bundle of pleasure.

Frank watched for a moment, grinning at the three couples, then left the room in search of someone to unload his cock into.