Barney spies on Marshall's professor and points out all her cougar traits.

The gang surprises Lily at her new job.

Barney ends up in the hospital after having sex.

Barney has a difficult time pleasing Marshall's professor in bed.

Ted and Robin talk about their first fight.

Ted's parents have a difficult time speaking about uncomfortable topics.

Ted finds out that his father cheated on his mother.

Barney tells Lily that she can get rid of women better than porn can.

Lily and Robin find out that the man laying in bed is not Ted Mosby.

Lily moves in with Barney.