I highly doubt the OP's ENTJ admirer is worrying about anything serious or long-term. So chances are, he just likes you and just wants to enjoy you for now.
But yeah, in case it ever does get more serious, watch out for the clinginess. My ENTJ ex was horrifyingly clingy (although he wasn't inexperienced, so that's no excuse). And as another ENTJ, I couldn't even deal with it.
Turns out we just had different expectations with our relationship. He was starting to bring up marriage. I ran like fuck. lol
Like I said, he probably just sees you as an interesting woman that he likes to go out with, and that's it for now. So don't worry too much. Just have fun and play the field.