Baby Marvin's bout of constipation stresses Lily and Marshall.

Even though Ted and his new girlfriend share none of the same interests, Barney urges Ted to sleep with her, until they find out she is Barney's half-sister.

Meanwhile, Barney attempts to hide the fact that he and Robin used to date from Quinn, but Quinn learns the truth when sleep-deprived Marshall and Lily accidentally blurt it out.

Barney prepares a comprehensive pre-nup, causing the other guys to think about relationship amendments for their significant others.

Meanwhile, Marshall has some embarrassing moments at an art gallery opening where Lily is battling to make a good impression.

Barney reluctantly attempts to sell his apartment by holding an open house, during which Ted and Marshall get mistaken for a couple.

Lily gets a surprising new career opportunity when The Captain offers her a job as his art consultant.

After Ted and Jeanette part ways, Barney steps in as matchmaker using the supposedly-destroyed Playbook.

Meanwhile, the rest of the gang reminisces about their run-ins with the law as teenagers; which leads to a debate over who was the biggest delinquent.

A determined Robin goes to great lengths to get back together with Barney.

Ted and Barney notice a beautiful woman wearing a puffy coat and become obsessed with finding out what she's hiding.