Relationship with Grace
Grace meets Nathan after he takes out her wet laundry out of the dryer she was using to put his in. She confronts him at his apartment and ends up helping him plan his romantic move on his girlfriend Vicki. Nathan later invites Grace to dinner at his apartment which was set up like the Grand Canal after Vicki walked out on him. Grace was repulsed by his sloppy sense of romance but still agrees to go on one date after he steals a kiss from her.
Still embarrassed by her attraction to Nathan, Grace tries to keep the relationship secret from Will but later admits it after Karen sees them having dinner. Will, who was dating a much younger guy makes an agreement with Grace to stop seeing guys who embarrass them. Grace, however could not resist Nathan and starts to date him openly afterwards. Although Will still finds Nathan repulsive, he lets him move in with them after Grace finds out Nathan was still living with his ex-girlfriend.
While things were becoming serious with Nathan, Grace abruptly breaks up with him and decides to go on a trip to Morocco. Will confronts her about it and she admits she is scared Nathan is changing too much of her life but also that she still loves him. She decides to stay with Nathan and they begin to take the relationship seriously.
While having sex, Nathan accidentally asks Grace to marry him. She is offended, questioning if Nathan even meant it so they decide to pretend it did not happen. Grace, however soon realizes she does want to marry Nathan, even if it means proposing to him herself. Nathan, who has had time to think things through, confesses their relationship have become too complicated, when it was supposed to be "easier". He finally breaks up with Grace after she asks him to marry her.
They later find out that he has started dating a girl named Suzie after four days and was going on a trip to the Bahamas with her.
Nathan is mainly portrayed as very charming yet childish and crude, which Will usually finds distasteful. Will openly resents his unsophisticated personality but later learns to appreciate how interesting he really is. Nathan shows a deeper side during a memorial for Jack's biological father after finding out he is dead.
After finding out how many people he has slept with, Karen says it is because Nathan is "not that interesting and sex is really all [he has] to offer".
- He's a vegetarian.
- His last name is never revealed.
- He has a T-shirt that says "Your mom's hot."
- Karen has described him as "the hottie who smells like rope".
- Will mentions that he throws lizards down the mail chute and races them to the lobby.
- He has a "happy dance" which he does whenever he feels extremely happy.
- He's into zen and likes motorcycles. He hates watches.
- As of dating Grace, he has had sex with five people in his life but has had 4,105 sexual encounters.(He tells Grace it was 3,105 but he admitted to Karen that he shaved 1,000 off. 
- Megan Mullally's husband-to-be Nick Offerman would have been cast as Nathan if Woody Harrelson had turned down the part.
- The Young and the Tactless
- The Last of the Really Odd Lovers
- Sons and Lovers
- Past and Presents
- The Third Wheel Gets the Grace
- Loose Lips Sink Relationships
- Rules of Engagement
We're born, we grow, we live, we die. If we're lucky, we have family and friends who know us and love us. I never knew my dad. But it doesn't matter, because wherever we go and whatever we do, we can know that the spirit of the mother and the spirit of the father are alive in each of us. That everything good already exists within ourselves. So, here's to Joe... the father in all of us. — At Joe Black's impromptu memorial, Sons and Lovers
We're not gonna hide who we are, ok? I mean, we date, we're straight, get used to it. — The Third Wheel Gets the Grace
There's no way that we're gonna have sex together after I've helped you pick out dresses for five hours. — At the Barneys sale, The Third Wheel Gets the Grace
- ↑ 1.0 1.1 1.2 Sons and Lovers
- ↑ The Young and the Tactless
- ↑ 3.0 3.1 3.2 3.3 The Last of the Really Odd Lovers
- ↑ Rules of Engagement
- ↑ Bed, Bath and Beyond
- ↑ 6.0 6.1 Loose Lips Sink Relationships
- ↑ The Third Wheel Gets the Grace
- ↑ 8.0 8.1 Past and Presents
- ↑ Nick Offerman On The Role He Almost Got On 'Will & Grace' (VIDEO)