Holden and Jack had a guys night out and just happened to show up at that place the 50s dance was held. When they walked in Lilly and Keith were dancing, and Holden went right up them and demanded Keith tell Lilly everything--about the guy with the gun in the room. Lilly knew all the answers, of course, that guy is (whatever his name is), Keith owes him money, blah blah blah. So b/c Lilly knew about everything Holden discovered by hiding in the closet he thinks he made a fool out of himself.
The last 20 seconds was interesting though. A guy met Keith outside and said how Keith's girlfriend would be mad about how all this was going with Lilly. And--Alli told Will she never wanted to see or talk to him again, and he looks like his getting ready to jump off the top of the building.
But for a Friday---nothing happened at all.