Paul is an eccentric character who makes fun of Ross whenever he can. A muscular, physically imposing man, he intimidates him very much and takes advantage of it. No matter how hard poor Ross tries his best to be polite to his girlfriend's father, Paul shows almost no hesitation whatsoever to snipe at Ross with mean and harsh words. When they first meet, Ross bemuses both him and Elizabeth with daft comments as he desperately tries to impress Paul.
Paul's wife had Elizabeth when they were very young and his wife died when Elizabeth was just a baby. As a result of this, he raised her on his own. He mentions having a sister who also died.
Paul stated his reason for disapproving of Ross's relationship with his daughter as being the fact that Ross was older than she was. However, Paul ends up in a relationship with Rachel, proving him to be somewhat of a hypocrite since he is considerably older than she is. This upsets Ross greatly, but Rachel convinces him that she can change Paul's opinion of him.
Eventually Paul decides to accept Ross and Elizabeth's relationship, but quickly changes his mind and tells Ross that if he doesn't end it, he will call the university Ross works at and have him fired, as Elizabeth is one of his students and Ross will be sacked if they find out he's dating one of his students. Ross and Elizabeth decide to continue their relationship in secrecy. One weekend they go away to Elizabeth's grandmother's cabin. However, Paul has decided to surprise Rachel and take her there on the same weekend. After trying to escape, with the help of Elizabeth and Rachel, Ross is caught by Paul. But not before Ross, who had been hiding under the bed in Paul's bedroom, saw Paul talking and singing exaggeratedly to himself in the mirror, revealing his cocky and deluded side. After Ross, in a subtle manner while in front of Rachel and Elizabeth, threatens to reveal this to Rachel if Paul informs the university of the relationship and has him sacked, Paul, out of embarrassment and fear, seemingly finally accepts him. Both of them, however, still do not like each other.
Later, Rachel starts to worry about her relationship with Paul because of how private he is. She tells him that she wants to know more about him and he tells her about the time that he was six and his parents bought him a "plastic chicken you hop around on" instead of Big Wheels like he wanted. He reveals that kids made fun of him and even called him 'Chicken Boy', making him a very insecure person. He begins crying for hours, revealing more about his childhood to Rachel. Even the mention of chicken causes Paul to burst into tears. It is also revealed that Paul had issues with his father who never hugged him. When Chandler walks into the room, Paul asks Chandler if his father ever hugged him, causing Chandler to reply "Did he ever hug you?" much to Paul's irritation and bemusement. However, Paul still asks Chandler to hold him, and when Joey walks into the room, Paul runs over to him and lifts him off of the floor while hugging him, too.
Rachel finally gets Paul to calm down long enough to have sex. But afterwards he can't keep himself together and begins bawling again. So, Rachel dumps him.
Paul is never seen or mentioned in the series again.
Paul's relationship with his family is explained throughout "The One With The Ring", where it is revealed that he had a difficult childhood and his parents were not very fond of him, like for example, when Paul was six years old, he told his parents that he wanted a Big Wheel, only for them to instead give him "a plastic chicken that you hop around on." It is also revealed that his father never hugged him, always saying "I'm a little busy here, Paul". It is apparent that they were very neglectful of him and did not show him much affection, which is most likely why he is so overprotective of Elizabeth. It seems that he had a good relationship with his sister before she died, due to his sad look when speaking of her with the gang.
Since Paul mentions that the cabin was his mother's and that he misses his father, it is likely that his parents are dead too.
Paul most likely had a good relationship with his wife. She died shortly after their daughter was born which was one of the few possible reasons why Paul was very overprotective towards his daughter.
Paul was very overprotective towards his daughter, likely due to the former having lost his sister and wife. He also did not approve of her relationship with Ross.
Paul had a strong dislike of Ross Geller. He claims that this is because of the age gap between Ross and his daughter while they were in a relationship, but his relationship with Rachel, who is considerably younger than he is, contradicts this attitude. Every time Ross tried to be polite to Paul, all the latter could do was snipe at Ross with mean and harsh words. Although Paul eventually stopped being nasty to Ross after the latter blackmailed him, the two of them still did not like each other. Presumably, Paul was pleased when Ross and Elizabeth broke up.
It is also highly likely and obvious that Ross was jealous of Paul due to the latter going out with Rachel, Ross's true love. Coincidentally, Ross showed obvious signs of jealousy like when Paul left him and Rachel at her and Joey's apartment, he kept asking "What the, how did...?" and when Rachel tells him Paul was looking for his keys, Ross incredulously replies "In your mouth?!" obviously showing disgust at the sight of Paul and Rachel kissing; so Ross was presumably happy when Paul and Rachel broke up.
Paul had quite a good relationship with Rachel. The two first meet at Central Perk while Paul is trying to find his keys and Rachel soon finds them. They soon start talking, and then... dating, something which upset Ross greatly. Throughout the rest of Paul's appearances, he and Rachel were happy together, until the former's last appearance when he starts crying incessantly about his miserable childhood. Rachel eventually gets him to calm down and they have sex, but Paul soon can't keep himself together and starts crying again, causing Rachel to break up with him.
Paul had less interaction with Phoebe, Monica, Chandler and Joey. He never spoke a lot with Monica and Phoebe (although it's safe to assume that Monica, despite like Phoebe appearing to be attracted to him at first, eventually took a dislike to him for the way he treated her brother), while with Chandler, they both had a brief conversation about their fathers: Chandler talking about his dad being in Vegas kissing other dads and Paul's not being so affectionate to him, and both of their dads never hugging them and then giving each other a big hug after Paul asks Chandler to hug him. When Joey walked into the room, Paul ran up to him and lifted him off of the floor while hugging him too, which left both Joey and Chandler bewildered as Joey and Paul apparently didn't even know each other that well, as Joey, while being lifted off of the floor, said in a confused tone of voice, "Hi, Paul, is it?" They understandably weren't very enthusiastic about the fact that Paul would probably be joining them and Ross at a Knicks game as a result. However, when Paul eventually put Joey down, Joey got so upset when Chandler then snubbed him that he ended up hugging Paul again.
- When Paul is apologizing to Rachel for crying so much, he says "when those gates open, it's hard to close them", a term Chandler used to describe himself after he starts crying in "The One Where Chandler Can't Cry".
- Bruce Willis allegedly agreed to appear in Friends as the result of a bet made with Matthew Perry when the two of them met while filming The Whole Nine Yards. Willis lost the bet and appeared in Friends for free.
- Bruce Willis is the main star of the Die Hard series which is coincidentally the three guys' favorite film.
- Although Paul is never seen or mentioned again in the series after "The One With The Ring", he is indirectly mentioned by one of the guys in the uncut version of the next episode having the water balloon fight who says to Elizabeth, referring to Ross "Whoa, Liz, your dad's a bummer", which results in Ross getting angrier and likely to attempt to attack the boy.
- Paul's antagonistic relationship with Ross is rather similar to the relationship Ross has with Rachel's father Leonard Greene - it appears as though Ross has a lot of bad luck when it comes to getting along with the fathers of his girlfriends. However Paul is a nicer person than Dr. Greene.
- If Paul and Rachel got married and Ross and Elizabeth got married, this is how their relations would have been:
- Ross would have become Paul's son-in-law and Paul would have Ross's father-in-law.
- Rachel would have become Elizabeth's stepmother and Elizabeth would have become Rachel's stepdaughter.
- Rachel would've become Ross's stepmother-in-law and Ross would have become Rachel's stepson-in-law.
- Ross and Rachel would also be ex-husband and ex-wife.