If you are secure in your relationship with your boyfriend, don't worry about it. It's okay for guys to have other friends that are girls.
Then be suspicious. He may have another girl friend.
find another girlfriend
If this is only one time, don't worry about it, but keep watch because if it happens again, you know something is wrong.
Trust him unless you have reasonable doubt about the innocence of their friendship.
Talk to her as friends and don't go no farther until they break up or you can find another dream girl.
From a close friend or a boyfriend a girl wouldn't mind. If its from a girl to another girl she may not like it. Also if you are not particularly close friends. Just be careful because for a girl to let another person do that usually they have to be a boyfriend or an old friend.
Explain that the other girl is just your friend then kiss your gf
Enquire,watch his movement's spy his mobile.text messages and find it out from his friends.
If he wants to marry another girl he's not your boyfriend.
I wouldn't but that is just me. If I were your boyfriend I would cry. It's not like he likes her more than you otherwise he would have broken up with you.
You should ask him if he likes the other girl. If he does then maybe you shouldn't go out with him anymore if he likes another girl. Or you should figure out what the HUG was all about. And also what the other person said above.
Let's see, if my boyfriend went to the movies with another girl, I'd slap him and never talk to him again. -- You could do that, or you could take it slower. First you talk to your boyfriend. If he tries to apologize, tell him it's about what he does, not what he says. Talk over why he did that. Maybe they went as friends, who knows. Then talk to the other girl, only if you're friends though. Be calm and collected about it. -- Of course, if he refuse to talk, then forget it. He's not worth it.