After sales for their hangover cure are slower than expected, the guys decide to take part in a drug trial for quick cash, but their plans are unexpectedly derailed by Paul Abdul.

When Kelly gets invited to her ex-boyfriend's wedding in Mexico, she doesn't want to show up alone – so she decides to bring Cooper as her plus one.

Cooper faces the ultimate, life-halting devastation when he loses his phone, and the guys stop at nothing to help him get it back.

When Barry and his Cooper Barrett's Guide To Surviving Lifefriend, Ashley, seem to be moving too fast, Cooper, Neal and Kelly try to intervene before he gets in too deep.

When Kelly tells Cooper that the state of his apartment is ruining their chances at taking their relationship to the next level, he sets a meeting with their landlord, Virgil, in an attempt to fix things around the gang's place. But after their first meeting takes a turn for the worse, an epic battle between landlord and tenant ensues.

When Cameron, the gang's old friend from college, wants to crash at Cooper's apartment, everyone is excited to see him. But after he quickly wears out his welcome, the guys will try anything to get him out for good.

Cooper suffers public humiliation when his ex resurfaces; Kelly meets a man whose love of competition rivals her own; Josh tries to exclude Leslie from group activities.

Cooper gets all the credit for Barry's grandmother's hangover cure, leaving Barry and Neil frustrated; the gang bands together to stop a rival CEO from stealing the hangover cure crown.

When Cooper and Josh's parents visit, the boys try to behave, but the revelation of a secret leads to mayhem and a run-in with rapper Juicy J; Barry helps Neal with an addiction.

Neal refuses to work with a potential buyer for Barry's Grandma's Hangover Cure; Kelly is obsessed with what's behind a secret door at Josh and Leslie's place.

Cooper and Kelly try to make each other jealous by pretending to enjoy dating other people, while Neal and Barry end up dating a polyamorous girl together

When the gang throws Cooper a surprise birthday party, things go south after Kelly witnesses Cooper and Ramona sharing a kiss