Boyfriend looked at another girl and she couldn’t help but smile?

We were in the car and he looked at her like why does he even have to look she’s literally just sitting there. He’s been caught doing this many times. It’s annoying and hurts me. The point is she smirked at me. He then proceeds to tell me “he thought she was an old lady” which just isn’t true. He couldn’t help but smile as well because he just got a huge ego boost. I’m not hurt about the glance at this girl but it’s just the disposition of letting her have one over me. Why would my boyfriend want another girl to think that she’s better than me? Which her reaction was to smirk at me about him looking at her. I feel insulted by him and especially her. What should I do?
Boyfriend looked at another girl and she couldn’t help but smile?
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