Nah, I think that by accepting a naked massage they already know what they are getting into. It just makes it easier because they can kid themselves it is all about them being pleased rather than being expected to do anything in return.
I had a straight guy on Monday who had no intention at all of reciprocating but once I had him oiled up and horny as hell he was well up for wanking me and, ultimately, sucking me. Afterwards he said it was the best orgasm he had ever had.
I have been chatting with another straight guy tonight who is happy for me to massage him in whatever way I want, including to orgasm. He has reservations about doing anything to me but does want me to be naked. I am willing to bet it eventually goes a lot further than just a massage.
I will report in next week after the meet