Season 11: Episode 4 - Clank, Clank, Drunken Skank

Clank, Clank, Drunken Skank: Walden begins spending time with Jenny and her wild friends as way to make up for never partying in his twenties. After a crazy night, Walden and Jenny wake up in bed next to each other, both naked and unable to recall what happened. They review the tape from the video cameras Charlie had previously installed in the bedroom and discover they were involved in a group orgy, but did not actually sleep together. Meanwhile, Alan is left sexually frustrated after Lyndsey continues to stand him up because of her boyfriend Larry. When Lyndsey meets Alan at a hotel to finally do the deed, she notices that Stephanie, the local gossip, has spotted them at the bar. In order to prevent her from suspecting an affair, Lyndsey sets up Stephanie with Alan. Alan finds Stephanie to be obnoxious and grating, but he sleeps with her anyway to maintain his cover. Lyndsey reacts badly to the news as she had only intended for Alan to go on an innocent date with Stephanie, so he loses his opportunity to sleep with Lyndsey once again.