Most Helpful Guy
Unless they are all over each other in front of everyone, it seems like she is controlling all this. Friendships can't exactly work when they are under control of someone else. But it's not as though she would allow him to see you without her presence as a chaperone. You can tell them that as an ex it's uncomfortable seeing them all over each other all the time and ask if they not do it when with you. If she insists on her right to do this, you have the option to excuse yourself. If that happens there's a chance that he will see how much she is controlling him and stand up to it for a change. Whatever happens, keep in mind that most guys will put up with only so much control. When that happens and she's out of the picture, you should be able to resume your friendship without all this foolishness.