Girls always flirting with my man

Sa

Hey ladies so I have a question on how to deal with other girls flirting with your man. In the past week two girls have flirted with my man. He is out of town for the summer and we’ve been doing long distance almost 3 months. I fully trust him and he trusts me. It bothers me so much when other girls flirt with him. I have witnessed it even when I was with him and she didn’t stop. My boyfriend is a very friendly guy and can confuse a girl thinking he’s flirting back. He’s not sis. He will shut it down by ignoring the person (depending what the situation is) or just giving them short answers. I know I’m not the prettiest girl and still have no idea why he chose me considering I’m like 4/10 and he’s a 20/10 lol. I can’t help but being bothered by that fact and not being there to do anything about it. Any tips on how to get over it and not sound like a crazy girlfriend?