Work problems

So I got a new job which is my dream. I am really happy and thrilled to be working there. So we had a Christmas party, all people in the company. And there is this guy who is not my boss, we are not working in the same department but I help them out when I can (working on Tv). He has been really friendly to me and texting me from time to time, I thought it was on a friendly base. I am 20 years old and still in college and when we were smoking he told me he knows my professor who is in relationship with a student and I said that I think it’s weird because of the age difference.. so at the party he told me they are going to an after party at his apartment, I wasn’t working next day so I went. Everyone went home at one moment and we stayed and kissed. I thought it was weird but we have really strange connection. We have seen each other 2 times more not in a work way, and not public. I don’t like my private things public and also he is much older. I don’t want people to know this in our company because of the age difference and I am new and don’t want people to see me like I want to become someone big through sex.

I am really torn between this, please give me some advice 🙄