One thing leads to another.

Lucy starts bobbing on your cock with the skill of a girl who gets a lot of practice. You shudder as her lips pass back and forth over the sensitive spots on your cock, and you groan as she hums: the vibration adds a lovely quirk to the sensations.
"God...damn girl...."
"Yeah...you shouldn't have shut me down for so long..." she twist-pumps as she smirks up at you. "See what you've been missing?"
"I'm a.... happily....fuck.....married...." your knees get weak.
"If I had a dollar for every time a guy told me that, James...." her smile fades... "well, I'd have like 15 bucks, but still..."
"Stop talking about other guys you've fucked..." you put your hand on her head and push her back down onto your cock.
After a few minutes, with her settling into a nice rhythm, you decide you've had enough of just her mouth.
"Let's take this somewhere more comfortable, Luce..." your voice is a little hoarse. Your throat is tight and dry.
"I thought you'd never ask, baby."
She leads you quickly into the first door on the right after the laundry room. the sounds of Ana's moans waft down the hallway. The bedroom Lucy pulls you into is nice and neat, clearly not used overmuch. "My room, when I still lived here..." she says offhand as she bends over to peel down her panties, giving you a show of her monumental ass.
"Fuck, baby..." you step forward, letting your robe drop and boxers, too. You rest your cock in between her cheeks, hot dogging and squeezing her plump cheeks.
"That's the idea, big guy."

She climbs onto the bed: face down, ass up, as the song says. You need no further encouragement, and you squelch the tiny voice of reason that's screaming {if Morality < 33
} for you not to do this.{else} that this is too dangerous. {endif
} You rub her entrance, spitting on your hand to wet your cock with, and then press on into her inviting cunt.
"Fuuuckkk...yes baby...give me that good dick."
You do just that, pounding that lovely cushion for a few minutes, enjoying the depravity and pure animal pleasure of conquering this little temptress. In no time, you have her moaning and whimpering, and whispering encouragement when she can.
"Fuck me good baby...you deserve it..."
Whether you do or not, you're taking what's been offered. For a few minutes, nothing is heard but the wet "slapslapslap" of your hips against her pillowy ass, the cute moaning squeaks she occasionally makes, and the erotic sound of heavy breathing.
"Can't...believe...I finally...got....James...Sinclair...in my bed...." she moans, almost as if to herself.
"What's that mean?" You ask, flipping her over to take her in missionary, with her legs elevated on your shoulders.
"Ana and I...have....a long...fuck....standing...wager...." she grins. "About who could get you first..."
"Oh...so I'm a fucking bet, am I?" You pound harder, and she winces as you bottom out.
"Ow! No...I wouldn't fuck you if I didn't think you were hot, baby. And I don't fuck assholes either. You're sweet. It's just...mm mmm mm mm...." she loses her words for a bit, but then continues. "You've always been kind of....untouchable. Hot wife... solid guy.... never thought I'd get you...."
"Well..." you say as you pick up the pace. "Guess I'm only human after all..." Once that ass was revealed in all it's glory...you really had little chance.
"They always are...eventually...." she smirks, before her face contorts into the beginnings of an orgasm... "Fuck, baby...don't stop....I'm going to cum...please don't stop."