He was an older brother to Paul Riesling, swift to defend him, admiring him with a proud and credulous love passing the love of women. (5.3.19)
For Babbitt, there's no person in the world more important than Paul. In fact, Babbitt cares more about Paul than he cares about women, and this apparently includes his wife, Myra.
"After twenty-four years of that kind of thing, you don't expect me to fall down and foam at the mouth when you hint that this sweet, clean, respectable, moral life isn't all it's cracked up to be, do you? I can't even talk about it, except to you, because anybody else would think I was yellow." (5.3.35)
Babbitt feels like Paul Riesling is the only friend he can truly talk to about his dissatisfaction with his boring life of business and family. Paul, though, isn't going to cheer him up just because he's a friend. If anything, Paul complains about his life even more than Babbitt does.
Babbitt was fond of his friends, he loved the importance of being host and shouting, "Certainly, you're going to have some more chicken—the idea!" (9.1.1)
Babbitt loves to laugh with friends and have a good time, but not necessarily because he likes people so much. The thing he loves so much about company is the fact that friends tend to distract him from the things he doesn't like about his life.
He was dismayed by a sudden contempt for his surest friends. He grasped Louetta Swanson's hand, and found the comfort of human warmth. (9.1.50)
As he becomes more and more rebellious, Babbitt realizes that he doesn't actually like half of the people he has always considered to be his friends. To him, they're all phony and money-crazed. In these moments, he tends to reach out to other people in search of comfort. Especially women he finds attractive.
They looked at each other in a grin of understanding. Paul took the plug, gnawed at it. They stood quiet, their jaws working. (11.3.3)
Babbitt and Paul get a rare moment of happiness when they head off to Maine together away from their families. The two of them often talk about leaving behind their normal, boring lives. But ultimately, both of them know that they'll never be able to do it.
"Well, you know what it means to me, Georgie. Saved my life." (11.4.11)
In a tender moment, Paul Riesling tells Babbitt that their trip to Maine has "saved his life." Paul, you see, has an absolutely terrible relationship with his wife Zilla, which makes his friendship with Babbitt the greatest thing going for him… and maybe the only thing going for him.
Babbitt did not drive home, but toward the center of the city. He wished to be by himself and exult over the beauty of intimacy with William Washington Eathorne. (17.1.22)
Once Babbitt feels like he's become friends with a big shot like William Washington Eathorne, he decides to drive around by himself instead of going home to his family. Being friends with super rich people helps fulfill Babbitt's desire to climb his way up the social ladder. In other words, the only reason he cares about being Eathorne's friend is because the guy is rich.
But at the Roughnecks' Table they did not mention Paul. They spoke with zeal of the coming baseball season. He loved them as he never had before. (22.2.1)
Babbitt is devastated when his best friend Paul goes to jail. He dreads hearing everyone at the social club talk about the scandal. But the men, to their credit, have the good sense to avoid this topic and to talk about things that'll take Babbitt's mind off his problems.
Babbitt returned to his office to realize that he faced a world which, without Paul, was meaningless. (22.3.1)
Finally, Babbitt faces the fact that without Paul, his entire life appears to be meaningless. This is because Paul is the only guy Babbitt has ever been able to talk to about his negative feelings. With Paul gone, Babbitt feels like he's alone in an empty world. He's lost his only emotional outlet.
The assurance of Tanis Judique's friendship fortified Babbitt's self-approval. (29.1.1)
Babbitt spends a lot of his time looking for reasons to pat himself on the back. The friendship of Tanis Judique gives him a reason to tell himself "Good job, buddy," which is strange, considering that the two of them end up having an affair… not usually something you get mad props for.