I think some men are conflicted about touching other men, simple as that. I guess they’re worried about what it might indicate about their own sexuality, or how it might appear to others. Seems silly to me. Just as a data point, I’m a straight guy, and I’m not conflicted about rubbing suntan lotion on anybody – male, female, gay, straight, whatever. I may be sensitized to the necessity for suntan lotion because I burn easily!