My older brother was injured in a car crash 13 years ago and is confined to a wheelchair. He has some feeling in his legs but can not use them. As for sex, he is able to perform but not well, not consistently/on-demand and apparently has been losing function in this area for some time. Last night I spoke to him (arrangements for travelling to a wedding) and he dropped bombshells that A) for the past 4/5 years he's been allowing other men to pleasure his wife for him and B) would I be interested?! Apparently it took him and his wife a whole to get their heads round the situation but now she regularly (like once a month) has sex with other men - mutual friends and internet hook-ups. My brother sometimes watches or joins in as much as he can but not always. His wife brought up the question of whether I'd be interested in being one of her lovers and so he asked me. I have to say that every sensible bone in my body is screaming "no!" but something about the idea of having sex with my brothers wife that he knows about keeps turning me on. He wouldn't be involved, or even watching, but he'd know what we were doing and when. I'm genuinely considering it. Everyone seems to be being very level-headed about it. But I'm confused. Any advice? Advice from men in my brother's position would be really welcome.