We already mentioned how a man in love will try very hard to break into your friendship circle and win over all of your favorite people. On the other side of that, he'll also want you to be a big part of his group, too. He wants to share memories with both you and his best friends, which indicates that he's pretty madly in love.
If you're just as in love with him, you'll be happy to make conversation with his buddies, even if it means talking about things you're not necessarily into, such as sports, cars, or fishing. The fact that he wants to bring you into his world is a really good sign for the two of you as a couple and it's usually a promising indicator of a future marriage and very long life together.