Allison misinterprets the signals...

You spend a few minutes telling her about your plan to go to USD, and hopefully get drafted out of college as a pitcher. You were very good in high school, though of course, nothing is ever guaranteed. You talk about how you had to adjust your life when Jenna got pregnant. You had to grow up fast and face hard truths.
"I guess mom told me that story... I just never really thought about it from your point of view..." Allison looks thoughtful.
"Not everything's in our control, honey. And sometimes, we have to make the best of what happens." You stroke her cheek, trying to be supportive. Based on what you've seen, you don't think Jack is a very good father to her. And you think Karen tries to be her friend instead of her mother too often. It's a common problem for women who got pregnant young: they want to be their daughter's friend, sometimes their club buddy, rather than their mother. Luckily, Jenna did not fall victim to that with Riley. "No matter what you decide to do with your life, I'll always be here to talk if you want. Someone who isn't your mom and dad, you know? I promise that no matter what you tell me, I won't get you in trouble." Unless it's absolutely necessary, you tell yourself.
"Th....thanks... huh..." She smiles. "When did you get cool, Uncle James?"
You laugh. "I'm not now, and have never been "cool," Alli." You look at her. "When did you change from an awkward, bitchy teenager into a pretty young woman?" You brush her red hair back. Perhaps she's calming down now. What a good bit of adulting, if you can toot your own horn.
"You really think so?"
"Of course, honey."
"I can't seem to get the boys interested." she frowns.
"That's ludicrous. But boys are stupid. They only think with their dicks until their at least 25." You suddenly remember who you're talking to. "Umm..heh...what I mean is..."
"No...I know what you mean, Uncle James. I guess I need a more...mature guy." There's a weird tone in her voice, and her face is a little more intense now. Perhaps it's time to...
Suddenly, she leans forward and kisses you, gripping your arms and snaking her tongue into your mouth. For a second, your brain goes blank.
"Whoa..whoa whoa....honey!" You pull back, and Allison's eyes flutter open with surprise. "Alli! What are you doing?"
"I...I thought...you were saying...I...thought...you wanted..." she suddenly goes beet red. "Oh god, I'm such an idiot!" She buries her face in her arms, pulling her knees up to her chest. "I'm so stupid..."
"Hey, hey, hey..." you give her a hug. Poor confused little Allison. "You're not an idiot. You just got mixed up for a second, honey. You're so beautiful and you're a woman now, but I watched you grow up. I can't do that."
"You said boys were stupid...I thought.... and you said... you made the best of a bad situation with Aunt Jenna. I thought you were...trying to tell me something..."
"Oh Allison...I love Jenna. I didn't stick around for 20 years just for the kids or something. I'm sorry I should have been clearer." She's shaking in your arms. "Alli...please calm down."
"Are you going to tell her about this? Or my mom and dad?"
"What did I just promise, honey? I told you I wouldn't get you in trouble."
"For stuff I tell you, not...not that...."
You rub her back and pull her closer, and she wraps arms around you. "I thought we were becoming friends again, Allison. Aren't we friends?"
She nods against your shoulder.
"Alright...just... don't try to kiss me, and everything will be gravy." You let her go, standing up.
"Th...thanks." she wipes her face on her sleeve. "I'm sorry."
"Don't sweat it, honey."
You head to the kitchen to grab a beer. Jesus..... that was unexpected. Your heart is pounding and your face is hot. Allison is your niece. Allison is your niece. {if HallPass =1
}Your pretty sure that the "hall pass" doesn't extend to fooling around with your own niece. {endif
}
You keep repeating that to yourself, until the front door opens, admitting Jenna and Karen.
"Hello, baby..." Jenna smiles, giving you a kiss. You try not to look guilty as you look from her to Karen.
"How was your day, girls?"
"It was great. We saw three houses. I really want her to go for...." you let the story of their real estate adventures wash over you. Too many details you can't care about. "...Jack?" you realize you weren't listening, but you think you know the question.
"Oh, he wanted to hit the back nine, and I was tired, so he'll probably be a little..." as you're covering for him, the front door opens, admitting Jack. He looks...sleepy.
"Hey, Jack. How was the back nine?" You hope he takes the cue.
"Oh..it was fine, but I'm beat." He greets his wife, who appears stiff in her affection towards him. "I'm going to shower and take a nap."
"We're going to dinner tonight at a fancy French restaurant, honey." Karen says.
"Sounds great! Somebody wake me when it's time for that..." he climbs the stairs.
You make yourself a sandwich, then head downstairs to browse social media for a while.
The rest of the afternoon and evening passes uneventfully. Riley and Allison are planning to make tacos. Jared hasn't come home yet, but you guess he's working out the details of his upcoming move with his new prospective roommate.
You made reservations at Chat Noir this morning, setting them for 6:45 PM, so at 5:30, you shave, get dressed in a nice pair of slacks, and a deep blue shortsleeve button up shirt. Jenna brushes out her hair and puts on makeup, wearing sheer knee high stockings under a tight dress, with a garter thong and no bra as far as you can tell. Your mouth waters as you watch her dress, and she winks at you as she clasps her nylons.

You head downstairs where Jack and Karen are waiting. The smell of tacos lingers in the air, and the girls are eating by the poolside. Karen's wearing almost the exact same outfit as Jenna, though she's clearly wearing a bustier under her dress.
"You guys ready?"
"Abso-fucking-lutely, Jameson!" Karen pronounces with gusto. Jack looks a little sleepy. Probably still whipped from his encounter today.
Jenna comes down, and the four of you head out, taking an Uber so that you don't have to worry about driving home.