Cynthia returns to the party

As Vanessa gets back into the shower, Cynthia washes her hands and splashes some water on her face. She looks at herself in the mirror. What had just happened? She isn't really sure how to feel, but one thing's for sure - there's a wet spot in her bikini bottoms. She's glad for the opaque shower curtain in the ensuite as she sits mops up her wetness as much as she can with a bit of toilet paper and flushes it. Still, the remaining dark patch makes her feel exposed and ashamed. She'll have to find her bag quickly and put the sundress she arrived in back on before anyone has a chance to notice.

She tiptoes out of the room and to the backyard, which is now lit by some fairy lights and by the light from the fire pit, which everyone is sitting around. Her barely-clothed body shivers slightly in the night air. Fortunately, she's able to easily reach her bag and slip her dress back on undetected. Realizing that she's quite thirsty, she heads over to the drinks fridge. As she holds the door open, looking at her options, she becomes aware of someone sidling up to her and turns her head, startled.
"Oh! Jade," she says, "You snuck up on me."
"Cynthia, can I talk to you? Somewhere private?" Jade says in a serious tone. Oh shit, Cynthia thinks, Jade must have overheard Vanessa and I having sex. What the fuck am I going to tell her? That it's actually okay that I cheated on my husband because he's been having a months-long affair with the same person?
"Sure!" Cynthia replies, not letting her panic show, and follows Jade back inside. Jade leads her to the laundry room and shuts the door behind them. She turns to Cynthia nervously.
"Before I tell you this, are you in a good place mentally? Like, are you in a place to get some really bad news?" Jade asks. That's weird, thinks Cynthia, Maybe this isn't about me and Vanessa.
"Sure," says Cynthia apprehensively, not knowing what to expect.
"Okay then, first I need to know... did you have a threesome with Mark and Vanessa? Like half an hour ago?" Jade blurts out. Huh?
"No... Wait, what? Why would you ask that?" Cynthia asks. She's acting more oblivious than she is, but she IS genuinely confused now. Jade takes a deep breath.
"Okay, so you know how Mark said Vanessa threw up all over the bed sheets in the blue room, and that he'd put them in the laundry?" Jade asks. Cynthia nods.
"Well, I came in here to make sure he hadn't put the machine on the wrong setting or something, right? Because they're kind of expensive sheets and I didn't want them ruined. But the thing is, he didn't even put them in the machine. He just put them into the hamper that's in here," Jade goes on. Cynthia nods. Typical of Mark to say that he'd done a chore when really he'd done something else with the assumption that it'd get done by someone else (usually Cynthia) later.
"Gross," says Cynthia.
"Yeah, but that's not the main issue," Jade replies, "the main issue is that... Well, I took the sheets out of the hamper, and it struck me as weird that they didn't smell of vomit. Like, vomit usually stinks up a whole room, but I just wasn't smelling it. And I couldn't see any vomit on the sheets, either. But then I noticed that there was a different smell... I kind of unscrunched the sheets to get a better look at them, and realized that the sheets didn't have vomit on them at all. It was..." Jade trails off, obviously not wanting to say it.
"It was what?" prompts Cynthia, even though at this point she knows.
"It was cum," whispers Jade, "Like, a crazy amount of cum. And it was fresh, because it was still wet. I mean, think about it. Mark and Vanessa both weren't by the pool for a while, and then Mark comes back lying that the bedsheets are covered in vomit when really they're covered - and I mean COVERED - in semen. Cynthia, he's cheating on you. He's cheating on you with Vanessa."

As Jade finishes talking, Cynthia sighs and cradles her face in her hands, her brow furrowed. What was she going to tell Jade? Her plan hadn't accounted for anyone else finding out about Mark and Vanessa's affair.
"Cynthia? Are you okay?" Jade asks.