In her mouth.

You eye her parted lips with hunger as you step out of the tub. "I want that dirty mouth." She nods with a look of pure lust as she slips to her knees. She drops the dildo to the floor, carelessly, and takes your cock in one hand. The contrast between how her hand feels and how your hand felt is incredible.
"Give me all that tasty spunk, James." her tone is halfway between pleading and commanding as she works her lips on the underside of your tip, making circular passes with the flat of her tongue as she rubs your overfull balls. She makes the head of your cock disappear into her hot mouth, and slobbers like a porn star as she blows you with great energy. Her technique could use a little improvement, but you can't complain too much. The wrongness, the forbidden nature of what was happening, combined with the sheer...abandon that Tara is displaying as she polishes your pecker, is enough to send you to the edge within minutes.
"Tara!...Ah, I'm gonna..." just as you say that, she pops the head free, and starts rubbing that same under-spot with her thumb.
"Give it to me...I need it, James." you didn't need the encouragement. You crest the point of no return. Like a runaway train, your orgasm hits, and you send two or three good spurts into Tara's waiting mouth, coating her tongue and dripping down her chin. She sucks your cock into her mouth, rubbing your shaft vigorously as she milks you for the rest. Her technique, again, is not as good as Jenna's. (Don't fucking think about Jenna right now) But, she's hot and enthusiastic, and shes moaning the whole time, as her other hand has never stopped frigging, and from the way her body is bucking as she drains your balls into her mouth, you'd say she's hit her climax, too. You guess she has a thing for cum.
"Wow." she sounds strange, talking with a full mouth. Your cum was fairly watery this time, so it's swishing around in her mouth. She plays around with it on her tongue, then gets it down in one swallow, not even a grimace, and shows her empty mouth to you.
"Thank you. That was tasty! Jared's cum is actually pretty nasty. It's nice to taste someone I can legitimately enjoy."
You're coming back down to reality now, and fear and shame are starting to take over. "Oh God. What did I just do. Fuck...."
"It's okay, Mr. James. It's just a little fun. We both needed some release. I won't tell if you won't." She stands up, and plants a perky kiss on your cheek.
"Any time you need a drain, just let me know, big boy." Before you can respond, she exits the bathroom with an obvious bounce in her step.

You clean up the evidence of your little...encounter, get dressed and head out of the bathroom, and as you do, Jenna appears at the end of the hallway that leads to the entryway and stairwell.
"Ah, good morning, babe." she's dressed in an orange and cream sundress with floral pattern skirts, and she's lightly made up and her hair is held back in a simple ponytail. She gives you a little side hug.
"Morning." You smile, trying to hide the guilt of your little tryst. "You look nice."
Jenna smiles. "Thank you dear. Listen, I've got to run to the store to get a lot of groceries for this weekend. I'm seriously considering charging Jack and Karen for room and board." she chuckles, and then puts a hand on your arm. "Can you come with? It'll make things so much easier."