In a LTR with a girl for 2 years. I'm 25 and she is 22. She sporadically works away from home for 3-5 weeks at a time about 4 months out of the year. A year ago during one of these periods she met and started hanging out with guy A during periods of work who I have since met and hung out with.

Nice guy who is obviously into her. Up until this point none of this bothered me as I'm not particularly jealous and saw no signs of cheating.

Skip to a night 3 weeks ago where I met up with my LTR, who I knew was with guy A his friend and his friends girlfriend drinking. We were all chatting and having a good time, all around getting along. I was a bit behind on the drinking and was working to catch up. During this time guy A and my LTR go outside on several different smoke breaks together as they are the only 2 smokers.

As everyone gets progressively more drunk guy A and my LTR start playfully teasing each other and pushing one another on the shoulders and playing footsie type stuff. This is all directly in front of me and seemed to be 100% friendly. I ignored and continued chatting with the couple. Later on we all go out to a bar and LTR and I split off and have fun and everyone heads home.

My question is: Is her taking jabs and playfully pushing guy A like this appropriate behavior? Obviously I have considered the fact that she may be cheating on me with him while they are away working, but my ego may be clouding my vision when I say that objectively I'm better then guy A, so I consider this unlikely.

I picture their relationship as good friends where he is orbiting her waiting for a break up of sorts and her keeping him as emotional support / back up kinda thing. I hadn't thought of this at all until 2 days ago when we were chatting over text (she is away right now for 1 month) and during her days off she mentioned over text that she was out with guy A for some drinks. This prompted an odd gut sensation of something wrong. Not really sure what to think just trying to get some extra feedback. Much appreciated.