I haven't gotten fully into the role playing yet. Mostly I've just worn a few outfits that he found to be an incredible turn on.
I started with a classic - naughty school girl.
Simple. But works.
I'm not sure what I want to try but I'm pretty open to any suggestions he has. I love acting too so it'll be interesting to see if I stay in character or not. I got a new pair of boots that my friends say look a bit like dominatrix boots so that lends to an idea
As for the laughter thing - I guess biting your tongue or the inside of your cheek. Try thinking of something really serious. If you think you're going to laugh, dont think about laughing or trying not to laugh. For me that tends to backfire. Just think of something completely unrelated and distract yourself.