6x24/25 "The One with the Proposal"

Chandler takes Monica out to dinner where he plans to propose. However, as Chandler starts to broach the subject, Richard suddenly turns up at the same restaurant and the moment is lost. Returning to the apartment, Chandler starts to worry that Monica may be getting suspicious and, desperate to surprise her, pretends that he isn't interested in settling down. Ross finds himself rethinking his relationship with Elizabeth because of her immaturity, and when he finds himself in the middle of a water balloon fight, his fears are confirmed and he breaks up with her. Joey accidentally buys a boat at a silent auction, falls in love with the idea of being a sailor, and decides to keep the boat. Richard reveals he's still in love with Monica and is willing to give her the marriage and children she wants if she is willing to take him back. Chandler begins his attempts to make Monica believe he isn't interested in ever settling down, however this backfires and she begins to reconsider their relationship. Eventually, Chandler is led to believe that Monica has left him but then discovers that she has planned the perfect proposal for him, while she proposes to him, she cries and says "there's a reason why girls don't do this!". Chandler finally asks Monica to marry him and she accepts.

Note: This is Tom Selleck's last appearance as Richard.