parents don’t approve of boyfriend

so I’ve been with my boyfriend for a while now and I’m pretty certain he’s the one I want to spend forever with. I’ve never been with anyone so sweet and thoughtful or who treats me so well. I truly couldn’t dream up a better boyfriend. the only problem is that my mom and dad are very critical of his appearance. he’s a “car guy” so naturally he has oil on some of his clothes. he doesn’t have a great sense of style and he tends to wait just a little too long between haircuts lol. for some reason these superficial and minor things cause my parents to be really judgey. my mom constantly says stuff like “what was he wearing last night, I can’t believe he leaves the house like that” or “you know there are other fish in the sea right?”. it’s really hurtful to me because I love him and I personally think he’s very attractive, but even then his appearance doesn’t matter to me. I know I can’t really make them see what I see but I want them to stop being so rude about it. it really makes me feel shitty. if anyone else has been through something similar or has any advice on how to not let it get to me I would really appreciate it. thanks! 💕