Yes, sex researchers conduct surveys, but sex is a very personal matter and people are not completely forthcoming about their sexual behavior and fantasies. In general, a lot of fantasies and practices are more common than you might guess. This is especially true for fantasies. If it turns you on to think about it, great! A side note: if you want to move out of the realm of fantasy and start thinking about making your fantasies real, you need to look at something very important: consent. If the sex practices you want to engage in involve other people, you need to get their consent before you engage in them.