Ohhh girl, I've been there. You want to talk about parents being strict? meet mine. Anyways, it's always going to be hard for parents to accept that their little girl is growing up and getting into relationships. If you met this guy over the internet and he's coming to visit you, I say this relationship of yours is pretty serious. I mean, come on, no guy will make such a big effort to show his face to a girl he met on the internet if he was not serious himself.
I know that I'm against lying (but what can I say, as a human, we still do)... I think it's best to tell them that he's just a friend. If your parents are strict, chances are.. they need a lot of time to absorb that you have a boyfriend. So in this case, take it slow. Let them know that he's a friend you've had for a long time. Once they start becoming comfortable with him, then you can let them know that you're dating this boy (not soon though, maybe a couple of months). As I said, you have to give your parents some time.. and when I say "time" i really mean it. I don't know how far you can go by talking to your parents and really telling them the truth. If you do, it can lead to two things. 1.) Theyll come to accept that you have a boyfriend OR 2.) They will totally make sure that you end it. Of course, we hope for the first one, but really.. you'll never know.
Whatever you feel is right, I say go for it. Don't ever put anyones judgements over yours. You know your parents the most... you'll figure things out soon enough.