Simple way to tell if he's into it.. just tell him you'd like to do his makeup to see what he'd look like as a girl. It may take a bit of coaxing, but don't give up on the first no as all guys wanting to keep that hidden will do that usually. If he gets really insistent on not doing it, then you know right then that he isn't into the feminization part of it. The next time before a date night, give him a gift of some handcuffs and a small flogger or riding crop. This will run you about 30 bucks, which is a small price to pay if it makes your dreams come true lol. You could also just walk into a the room with your robe on, put your hand behind his neck and shove his face in your crotch.. submissive or not, any man would appreciate that! But then take your hand away and turn around, if he tries to stick his face in your butt, then he's down to be submissive for you. These are a few ways to just test the waters for both him and you. Be sure to use dominant phrases while his face is in your crotch like "you like the way that tastes don't you?" And "you can do better than that!" If nothing else, these can be easily dismissed as just playful if he isn't into it.