Don't go to HR unless there's harassment (and know what that means in an HR context). To find out why this guy is acting a fool, ask him. Ask if you can speak to him privately and confront it. One way to do it would be to ask him to validate what you're thinking - "at happy hour, you seemed unhappy that I was showed up. Am I misunderstanding?" And talk about it. If you must talk to someone without confronting the behavior directly, he is a vp after all so maybe you don't feel comfortable, talk to your boss.