My boyfriend is a bad kisser?

My boyfriend is super sweet and kind of shy and we are both 17. I have been dating him for a month and I am his first girlfriend and also his first kiss. He is so sweet and a like him a lot, but I can tell that he gets really nervous when it comes to stuff like this. The only way I can explain it is that he doesn't really move his lips hardly at all and it feels like i am kissing just someone who is puckering. I am not one to go straight for tongue or anything, but I would like some movement at least! Should I just keep kissing him, hoping he will get better or say something? I don't want to hurt his feelings though and i don't want to embarrass him. Any tips?