Tell Thomas to switch holes and keep watching

You move closer to the pair.

"Hey, Thomas, why don't you pull out of her?", you say, "I want to see your cock enter your girlfriend's ass."

Thomas does as you tell him, and pulls out of Emma's vagina. You almost forgot how enormous Thomas cock was. No way it's going to find inside Emma's ass. You watch as Thomas positions his member, glistening with Emma's pussy fluids, against her ass and starts trying to ram it in. When he finally succeeds, Emma's mouth flies open and she screams in pain.

"Ah! Fuck, sorry!" Thomas rakes his hands through his hair. "I forgot how much it disgusted you to have your ass fucked, huh?"

Emma nods. She's between screams, breathing heavily. "Fuck... ah... ah... ah... ooh... oh, fuck... my back... shit... Oof!"

You reach over to touch her shoulder. "You with me, girl?"

Emma nods.

Thomas begins to object, but you cut him off. "Shut the fuck up, loser. Tell me, is she tight?"

"Yeah, it hurts.", Emma answers, through breaths.

"Perfect. Then what are you worried about, dickhead? Fuck her in the ass."

Thomas nods and picks up the pace, with Emma's enormous breasts responding with a hasty "slop slop slop". After a few moments of grunting, Thomas begins to moan and tense up. He grunts one more time, then collapses on top of her. He remains still as he pants.