That night, Cliff shows up in Liza's garagabatory to menace her/profess his innocence. After he leaves, Liza discovers the bloody angel costume dress is gone. Oooh, another mystery! Who do you think took the dress? I say Nikki.
At Tess's party -- which is at Johnny's family's house -- Cliff tries to convince Johnny that Liza's not to be trusted, which I can't imagine would have much success. Then Johnny tries to warn Nikki that Cliff isn't to be trusted, which goes over just as poorly. Maria shows up and spies Cliff and Nikki making out, which you'd think would drive her into a fit of Middle-Aged May-December Lady Rage, but instead just leads to her and Cliff humping in her dead son's old bedroom. Nikki sees them, of course, but instead of falling face-first into some Cuervo, she waits for Cliff to find her later and reads him the riot act. While his denials are delightfully disgusting ("She's like a second mother to me!"), Nikki isn't buying them and she tells him they're finishes.
In "All About Skip" news, Bob tells Skip to keep his hands off his wife, Skip tells Johnny to be careful with Greta, and Tess's bid to make Skip jealous fails when he spots Tight Pants Steve getting handsy -- and later, lipsy -- with another dude. Maria sees him and says hello, and it's glaringly obvious that Something's Up when she's the only woman in the room he doesn't greet with a full-body canvass. Later, Skip tries to dance with Karen, and he's all aggressive and drunk and his hands are all over the place, and Bob spots them and hauls off and clocks Skip in the jaw. It leaves a big ol' mark on his face, but it doesn't seem to hinder him any when he ends his night by planting a big fat birthday kiss on Tess.
Liza shows up at the party and Johnny manages to prove he actually is just as dumb as Cliff thinks by questioning Liza's motives, accusing her of jumping to conclusions, etc. Skip overhears this whole conversation, by the way. When Greta shows up, Johnny tells her that between her version of events and Cliff's, not to mention how he's an easily-manipulated dumbass, he just doesn't know who to believe. And, yes, Greta does respond to that by flouncing off in a huff.
Outside, Johnny finds a sobbing Nikki and tries to comfort her. She tells him about Cliff's cheating and says it was with the mother of the kid who used to live in Johnny's room. To Johnny's credit, this actually registers as A Big Deal, and you can almost hear the groan of the gears turning in his head.