What do I say?

So me and my boyfriend are in a long distance relationship, which makes things a little tough stress wise. We see each other maybe once or twice a month, which isn’t bad. But he told me he wanted to try new things in bed, which I’m totally down for. And so far it’s been amazing. But when it comes to adding little sexy comments during, my mind goes blank. So I suppose what I’m asking for help with, is what I should say that helps keep the mood.