To get plowed, obviously.

Kayla pulls you to your feet, and then takes your place, laying with her upper body on the seat, still warm from your ass, and she pulls up her skirt, exposing her gorgeous ass in a black lace thong.
"Let's christen my new car. Fuck me, James." She pulls down her panties and wiggles her rear, waiting.
Oh, christ. How could you resist that?
You drop to your knees, aligning your cock with that inviting slit, and you begin to rub the head of your cock up and down from clit to taint and back again.
"Oooh...that's right, stud. This is what you can have when you're such a good boss." She peeks over her shoulder at you. "What are you waiting for?"
"Nothing." you shove your prick inside that tight, slick tunnel, and Kayla's eyes roll up in pleasure as she starts to moan.
"Yes...that's so good." she's a goddess, gyrating her hips and undulating as you fuck her gently at first, but with increasing fervor as you get comfortable. "It's been so fucking long..."
"What, no gentleman since...?"
"Nuh-uh. Just Mr. Pink Rabbit and Ms. Fingers. I could never go all the way and bring...UHNG! FUCK that's good...bring a guy home..." she's trying to speak coherently, but you're making it difficult. "I guess I just needed a Sinclair dick." She makes a kissing face over her shoulder as you plow that pussy. She definitely has been sorely in need of a dicking, because her snatch is quivering and gushing in no time.
"Aw....FUCK yes. James.....please dont stopdontstopdontstopdontstopimgonnaimgonna......." she let's out a feral, primal screaming orgasm, and you bottom out hard. You're about to cum yourself.
"Kayla, I'm going to blow!" You start pumping harder.
"Let me taste it!" She begs, still shivering from her own explosive climax. You pull out, waiting for her to get underneath your cock, and then you shoot a powerful load onto her tongue. As the first spurt hits her, she swallows your cock, sucking out the rest like a milkshake through a straw.
"OH FUCKING CHRIST KAYLA!!!!" You belt out at the top of your lungs. You're very glad there's no one within earshot right now. You fall back flat onto your ass, hard onto the concrete of the garage floor. Ow.
Kayla is panting, and swallowing the last bit of your spunk. "Wow James. A new car and a screaming orgasm from my first good dick in two years. How did a girl get so lucky?" She giggles, and starts to redress.
"Oh shit, girl..." you're starting to come back to reality. What have you done. "If Jenna ever found out about this..."
"Well, I'm not going to tell her, silly. And neither should you. I'm not some Fatal Attraction Glenn Close nutcase, James. This was...amazing!" she's wiping sweat and tears from her face lightly, and adjusting her bra before pulling on her sweater. "But I'm not looking for anything. I just thought you needed to know how much I appreciate your gift. And I definitely needed a nice thick cock in my vagina." She admires your diminishing manhood. "We can just pretend this never happened, go back to normal...well maybe with a little less bitchiness on both sides, don't you think?"
"Yeah." You have to agree, what choice do you have? You definitely feel the release of some sexual tension you've had with Kayla, that you didn't even notice until it was gone.
"Now get your ass home, before Jenna gets suspicious, tiger!" She winks, and gives you a hand in standing up. She gives you one more very sexy kiss, and then heads back inside.

You get into the Jav and head home, your head spinning. This day is not going how you expected. If you can't keep a rein on your dick, what is it going to be like having so many beautiful women around, never mind that one is your sister, and one is your daughter?

You spent too much time at the shop getting your dick wet, and you hit unexpected traffic on the drive back. You curse as you also realize you never fully gassed up the Jav, and so you waste more time trying to maneuver into a crowded gas station.
The result is that you pull onto your street to see the travelers have already arrived. Everyone is on the lawn, greeting and hugging each other. God damn it. You had wanted to be home when they got here.