Checking out other girls...

So last night was my bf’s close friend’s birthday dinner at a nice restaurant and I was invited to it as well. My bf and I have been dating for 3 years. When we were waiting outside of the restaurant and just talking to everyone, this girl wearing a white dress with lots of cleavage walked past...and he checked her out. That didn’t bother me because everyone looks and he didn’t look for long.

Once we got inside and were waiting for a table, the same girl was there waiting with her group of friends. And as I was talking to my bf, his gaze was on that girl for a lot longer. He has is hands in his pockets and was just staring at her and I’m guessing admiring her beauty. That’s what upset me...are there any ways to overcome this? I’m not jealous, its just a that I felt disrespected at the moment. What are some ways to get over this? And, am I overreacting?