I've actually been fucked by both a man and a strap-on on more than one occasion. I love it. I wouldn't call myself gay or even bi-sexual. Just fun. I also don't think it makes me any less of a Master. I think chances are that MrW has had a little poke of his own at one time in his life, (whether he remembers it or not) and he didn't like it. People are different. There's lots of people who don't like anal sex.

There's no rule that says that just because he's a man he should according to the manual enjoy this, that and the other. People are different. Especially Masters. I can't think of any other group of people with a more complex set of needs regarding their sex life

edit: Forgot to mention that according to Dan Savage it's only around 50% of all gay men who enjoy anal sex. Which would indicate that we, (men) are all very split on this issue.