You've seen enough.

You decide to intervene before this gets out of hand. You quitely exit the bathroom into the hallway, and then re-enter, making no effort to stealth.
"Scotty! You done man? Also, have you seen Jenna."
There's a muffled commotion in the bedroom as you open the door. Jenna's sitting on the bed, with her shawl wrapped around her, but the fabric is still moving. Scotty is across the room, leaned against your dresser.
"Yeah! Yeah all set, man!" he seems a little out of breath. "I was just...telling Jenna here, what I had to do. It'll be in the invoice!" You lock eyes with his. A little unspoken communication takes place.
"That's great man. You're a lifesaver." No change to your flat expression as you continue to watch him.
"Y-Yeah...no problem boss. I'll just write it up and leave the invoice on your table downstairs. Excuse me Jenna." He scurries into the bathroom to gather his tools.
When he leaves, you turn to regard Jenna, who's failing miserably at acting innocent.
"And...what was all that?" you cross your arms.
"What? I don't know what you're talking about." Her voice is a bit high pitched.
"Jenna you've got a terrible poker face." you soften your tone a little. If she fesses up, there's no reason for this to be a thing. "Everyone knows Scotty has a crush on you. What were you doing?"
Her face drops, and she twists the ends of her shawl like a 14-year old caught with her hand in the cookie jar.
"You were being such a jerk all morning.." her voice is quiet. "I thought I was just have some fun... flirt with him a little." she looks up at you. "It was just some harmless fun...."
"Harmless?"
Her shoulders slump a little. "I'm sorry... you're right. I don't know what I was thhhinking..." she lisps on 'thinking', "I drank too much wine too fast."
"Yeah you did. Alright, lush. Let's get down to the pool before you get yourself into trouble."
You head down to the kitchen, where Scott is writing up the bill for the bathroom.
"All set, Mr. Sinclair. Just settle up by the end of next week, cool?"
"Cool." you hold his gaze. "Will you be joining us for dinner, Scott." You keep a lock on his eyes.
"....unfortunately, I'm going to have to pass on that. Another time maybe." he doesn't break eye contact either.
"Oh? That's a shame. Have a nice day, Scott."
Jenna has a pout on her face as Scotty leaves.
"You didn't have to do that! I can behave myself." she punches you in the rib, but not hard.
"Get downstairs, Jenna." you smack her on the ass, hard, and she yelps.
"Brat..." she rubs her ass cheek and heads down the stairs.
Riley is taking dives onto the deep end now, and Allison is laid out next to her mom, who is slick and glistening from her swim. Jenna gets some praise and adulation from the girls for her bathing suit, and you pour yourself another margarita.