Bit of a stretch, but the whole premise in a way. Most of the guys have definite Jerkass tendencies, but they'll go to some pretty extraordinary lengths to find their friend.
The scene where Stu finally breaks up with Melissa - Phil's expression as he sees this is almost like that of a proud father, whilst Doug & Tracy are grinning & hugging Stu once it happens.
Adding to Phil's fatherly response, remember that throughout the movie Phil had been the member of the Wolf Pack most vehemently opposed to Melissa's treatment of Stu. Doug quietly disapproves, but doesn't voice it out loud and Alan doesn't really know the people involved, so he can't offer much of an opinion. Phil repeatedly and angrily calls out Stu on how abusive Melissa is and is obviously downright pissed at how his friend is being treated.
Phil spends the opening act of the first film complaining about being married with a kid...and is then really excited to see his family again and carries his sleeping son around for the entire end of the movie.
The third film has Alan reuniting with Tyler, aka Baby Carlos. Alan, being Alan, makes the kid believe he's his real dad. Before he leaves, Tyler hugs him, and Alan gives him the aviator shades he wore in the first film.
Alan and Cassie's scenes together.
"We're the three best friends that anyone ever had..."
In the first film, the way that Phil seems to take charge of the Wolf Pack after Doug goes missing. While Stu and Alan are more freaked out, Phil leads them around like an exasperated dad and keeps them focused on the task at hand. A stand out moment has to be when he calms Alan when the latter worries that Doug might be dead. It becomes Fridge Brilliance when you remember that Phil is a married teacher with kids of his own. He's probably used to taking charge in situations like these.
In the third film, after Marshall kills Black Doug he see's that Alan had wet himself out of fear. Understanding that the moment was scary for him, he asks his assistant to bring Alan a spare pair of sweatpants for him.