Tickle during ?

My boyfriend and I have been dating for about 4 months, and decided to take it to the next level last weekend. I feel completely comfortable and relaxed with him, with no regard to /ual activity. When he tried to finger me, it tickled so much, it made me cry. I have played with myself before, and have not experienced that before, although it is also unlikely for one to tickle themselves. Am I just naturally more sensitive in that area, or does it have something to do with comfort/relaxation. By the way, I am 21, and have not been intimate with anyone before him.