Should my boyfriend be jealous?

I just got a new job at Best Buy. They gave me my uniform and it’s a simple blue shirt with a small v neck and it’s slim. It’s an extra small but I’m also getting a size small. He told me that I’m going to attract people wearing that and he was getting really upset at me, asking why would I choose an extra small. I told him, “because I am an extra small? And I’m getting a small too but it just hasn’t came in yet? You’re really getting mad over my uniform?” And he even showed his whole family my shirt and said, “isn’t this too small? Like if she’s trying to get attention at work?” And I’m like what the hell? It seems to really bother him and I’m not sure what it is I need to do to not make this a problem. Is his jealousy reasonable?