Why do I feel like this is a weird question? It's probably not.
Firstly it's important to note that it's really different for everybody. For me, it really hurt...like a lot.
It wasn't until my like 5th time that I actually began to 'enjoy the feeling'. It depends on how turned on you are, what you've got going on under your pants and how 'big' he is.
The more relaxed you are with the person and the experience, the more likely it is that you'll enjoy yourself.