Lindy, there are ways you can both get physical pleasure from this act. The harness I own has the ability to hold two dildos, one for me and one for him. I have also set it up so that I can have a vibe going on me.
Plus, isn't a large part of any intimate sexual contact mental? Its not like I could have sex with anyone and feel as turned on as I do with smrt. The more he seems to enjoy it, the more I get worked up and thus the better my orgasm is when its my turn to be pleasured.