I need a surprise for my boyfriend while we're having sex.?

I told my boyfriend I'd give a surprise while we we're having sex. We've been together for almost two years now and I can't think of anything I haven't done before. We're in his basement and his parents are almost always gone or upstairs. They rarely bother us. The only thing that I've never done, is give him oral, but I just feel awkward doing it. I really need someones help. I'll appreciate anyone's answers. I can't do outfits or anything much because we're confined to his basement and his parents are home. Any ideas? I neeeeeeeed help, PLEEEEASE. :/