Some men would be intimidated by knowing they are first.
Being a virgin, you don’t know how you will act/react at that moment of truth. Lots of women have thought they were going to have their first experience, and at a certain point said, “wait, I’m not ready.”
Knowing your partner is a virgin can leave a partner feeling nervous too. More so at your age, because teenage boys are more concerned with having a moment than sharing a moment. An adult man is more likely to care about how his partner will respond, and remember.
I believe this is something you should discuss with a potential partner, so that both of you can explore whatever anxieties either of you might face. After all, it could be a first for him also, as first time with a virgin. Some men would love to be with a thirty year old virgin, but some would feel anxious about being on the spot.
I don’t know how long you have been involved with the man you have in mind, but I do get the impression you haven’t been dating anyone yet.
I would strongly advise you to date a variety of men before you make any choices. If you are simply wanting to get that first time done and over with, I suggest you find a fellow for hire. That way you can be sure of no attachment, and your partner for hire could give you some instruction. You could be fairly sure he would not feel intimidated.