Oral Sex Complications?

Okay, so I've never had anyone go down on me until this evening by my boyfriend. We ran into a complication though.

I was really sensitive, so it tickled. It tickled to the point where I couldn't take it anymore and I'd burst out laughing and I'd have to push him away. I haven't had an orgasm for a while, so I wasn't sensitive because of that.

My question really is, is this normal? And if it is, can I fix it some how? I'd like to be able to receive oral sex from my boyfriend without having to push him away because it "tickles".

Thanks!