As a male, I think most men interested in t-girls would want to play with it, since, as you put it, why not just go GG otherwise? But, men into only GG probably want to do anal from time to time too - but if the girl doesn't want to, that's that. It's your body, and you shouldn't have to do what you don't want to do. That's not what sex should be like. Besides, its not like he's making some big sacrifice - there's a lot more fun to be had in bed with you than that
Although maybe from time to time you can allow the guy to play with it, sort of as a favor, and put up with the discomfort. Of course, that is still completely up to you, but it might be a nice thing to do from time to time, just like a GG might allow the occassional anal.
