How to get over this insecurity?

I’m pretty insecure about my own body. I have smaller breasts and am looking into getting implants. However, my best friend is coming in from out of town for the weekend. She has very big breasts and likes to show them off. Not just cleavage. But boobs literally hanging out. She is a bigger girl and I am a smaller girl in terms of general body size. But I am insecure that she will dress inappropriately the whole time she is staying with me and my boyfriend. I am nervous that he will start to not like me because of my smaller breasts. I don’t want him to think about her while we are having sex or think about her while he’s masturbating.

•I know this sounds ridiculous. I know that it sounds crazy even. I hate feeling this insecure. Please don’t be rude•

He does have a porn addiction. So he has probably seen it all. And still chose me. So it’s probably nothing new to him. But just the thought of having her stay in our house for 2 nights might make it more “special” or something. •How can I get over this insecurity? How can I have fun with my best friend while not getting completely insecure about my boyfriend?