I've gotten turned on many times seeing myself in a mirror, usually acting out some fantasy so that I can see what others would see if they were present.
One of my recurring fantasies grew out of a "Sadie Hawkins Day" long ago at my high school. We were in journalism class and the teacher was often out of the secluded classroom. Six of the girls put on lipstick and surrounded me at my desk and smothered me with kisses while a seventh one took photos.
I loved it, of course, but I think the camera and the fact that they wanted to embarrass me a little is what helped it grow into a mirror fantasy. Over the years, it morphed in my imagination to a CFNM thing, where some of them hold down my arms and the rest pull down my pants (kind of like that scene in "Myra Breckenridge") and start playing with me, laughing and teasing my balls, then one of them starting to put things like pens in my ass...culminating with her dropping her own skirt and underwear, putting on a strap-on, and putting it inside me, saying, "You are really going to enjoy this, like it or not." The others would scream and laugh as she starts thrusting, and so would she, like Raquel Welch in the movie.
In the mirror, I like to see parts of my body I normally can't, as they would...and things going into and protruding from the back door.
I'm thinking about asking my wife if she would use a strap-on on me if I buy her one, and filming us in a bathroom with plenty of mirrors.