Dating opinions

Okay, so I've hit that point where one of my male best friends has gotten a girlfriend. What's so bad about that? Well, nothing really, except for the fact that he hangs out with her 24/7 and completely ignores his other friends, especially those who he's known for longer than he's known his girlfriend, let alone has dated her. It's frustrating because I used to be able to talk to him about things that have been going on in my life and ask for advice; now I can't do that because he devotes all of his time and energy to his girlfriend and his girlfriend's friends. While I agree that when you are dating someone, most of your attention and energy should be devoted to them, but I don't think that they should do that if it is at the expense of ignoring friends.