While driving around town with said "girlfriend", pull into the parking lot of an Adult Novelty store. If she responds with "Don't go in there, you freak!" reply "Oops! I thought this was the Piggly-Wiggly store!"
If she responds with "Why are we stopping here, <sexual pet name>?" reply "I thought it would be a good place to get gift ideas!" If she responds with "For me???" you reply "Let's see if we can find 'something' we'll both enjoy!"
After entering the store (and getting your bearings, seeing if there is a guy or girl salesperson, etc.), move toward the BDSM section. If your girlfriend headed straight for this section, you have your answer already! If she follows you shyly, offer her this proposition "You pick something you'd like to use on me and something you'd like me to use on you. I'll do the same and we'll see what we find!" Depending on her choices, you'll know whether she has submissive or dominant tendencies!
Try not to "steer" her. Let her sexual mind "spin" on it's own -- she may surprise you!
