When guys are younger, it's almost a requirement for them to show they aren't under the authority of their girlfriend or wife. It's almost a rite of passage. It doesn't mean they are cheating, though that happens often enough. It's a tough time for relationship building, but guys, when they're young, absolutely have to sustain their close friend relationships, and many times those connections will seem to outweigh the connection with their girlfriend or wife. It doesn't mean they don't love you, it just means it's another part of the male maturation process.