Samatha.

Unless you suddenly mutate a second penis you can only fuck one of the girl's pussy at a time — the position they are in will test your endurance as you try to please both of them. Since Erin was last to have your cock in her you decide it only fair to give Samantha a turn at your cock.

"UMPH!" the redhead moans into her lover's mouth when you unceremoniously shove the full length of your cock into her pussy, soaked with her juices and your saliva. Resting your hands on her ass cheeks, you starting pumping away.

"Fuck her hard like the way you did to me!" Erin orders.

So you do and it does not take long for Samantha to climax.

"Yeah, that feels good, doesn't it, baby?" the blonde purrs. "You love being fucked by a real... UMPH!"

You interrupt the blonde by jabbing your cock deep into her cunt.

"You love being fucked by a real cock too!" Samantha giggles as you madly thrust away at the blonde's hot, tight cunt.

Every time each girl cums you switch to the other girl's awaiting pussy, bringing her to orgasm before swapping pussies again. Eventually it becomes a blur, you lose track of whose pussy you are fucking and are just concentrating on lasting as long as your stamina can allow. However, it when finally comes to the inevitable you pull out and let out a roar as your cock spews thick jets of jizz on both of their reddened snatches.

"Holy shit..." you sigh, collapsing to the floor with your flaccid cock on your thigh.