My friend wants me to date this guy?

I want to wait until I'm eighteen to date a much older man (I find them more mature). I'm waiting because I know it would be weird and maybe illegal to date someone in their late thirties while I'm just sixteen. But recently I've been wanting to be in a relationship, I don't know why, I just want to have a significant other to do stuff, like go to the movies, to the museum and just be together.

My friend wants to match me with her friend who is seventeen, she always talks about him being the perfect guy for me. I met him once and he was kind of shy so we didn't talk but she said that he thinks I'm pretty. I talked to my mum about it and she said: 'Just tell her to stop, tell her that you aren't looking for a boyfriend.' I feel bad because she doesn't understand. I didn't talk back or anything, I just agreed. He seems really nice. I don't want to tell my mum about it because otherwise she'll be sad that I'm not her little girl anymore, all innocent and everything. I'm a really good person, I don't drink, I don't do drugs, I read 6 books a week and do ballet and I never ask for anything.

I feel like I'm growing up too fast. What should I do about this?