They fuck to completion

You and Erica begin kissing again and making out again, though with half an eye towards the spectacle of Simon plowing Heather right next to you.

Heather's moans and Simon's grunt are the most sexually stimulating soundtrack you could ask for, and the sight of a huge dick ramming into a soaking wet pussy over from about a foot away is far better than any porn. Heather cums over and over, each orgasm an intense affair completely unlike the mild orgasms you give Erica by eating her out.

You find yourself rubbing Erica's hot pussy while she takes your dick between her fingers in turn. You cum instantly, but remain fully hard, and Erica's too invested in watching the intense mating show in front of the two of you to notice.

Finally, Simon cums inside of Heather while he hammers her with hard, deep thrusts, shooting his cum into the further depths of his pussy before slowly withdrawing his enormous manhood.

The sight of the titanic cock - covered in juices and dripping leftover cum - emerging from the depths of Heather's ravaged pussy is beyond erotic. Not only do you cum again, but through your fingers, you feel Erica's pussy quiver with an orgasm of her own. It's the first time you've gotten her off without your tongue, which goes to show how aroused she is.

Sounding a little winded, but mostly exultant, Simon inquires "so, now that we're all so much closer, what do you two think of trying 'clean-up'?"

He grips the base of his still-hard, juice-covered dick and waves it a few times in front of you and Erica, then gestures to the ravaged pussy between Heather's legs.

"There's one for each of you, so go ahead."

Though he's asking the two of you to go down on him and Heather while they're both still messy from their recent fucking, he seems to consider it a given that you'll be interested.

The truth is though...you are. Heather's pussy is still throbbing with arousal from her recent fucking, and you can't help but but by turned on beyond belief by the erotic smell of her juices. Simon came pretty deep inside of her, so you don't see any cum leaking out either.

Erica's of the same opinion as you it seems. With a glance, you can tell she's not against the thought of licking Simon's messy manhood clean.

She doesn't dive in though, instead giving you a non-pressuring look of 'do you want to do this?'. The amazing girlfriend that she is, Erica still makes sure you're okay with it before agreeing to place her mouth of the perfect specimen of masculinity before her.

On the surface, it's just a bit of swinging in the form of partner-swapping. And you're incredibly turned on by the thought of it. On the other hand, your small-dick-fueled insecurities tell you not to let Erica get a taste of big cock, worried she won't be able to stop herself from tasting it again in the future.