Good question in your title!
My OH rarely says point blank 'No' to anything really. He isn't that type of guy and since we have been together he has learned never to say never. But I know it is probably very unlikely to happen when I hear his tone of voice etc.
But he has completely refused my asking him to cross dress for me. He said he did it once for Rocky Horror, but that was for a laugh and all his friends did it too, and heck, it was Rocky Horror. He can't understand my thing for crossdressers, I don't think. But then I don't suppose that many people would since crossdressing seems to be very much accosiated with the gay community - stereotyping and all that.
I made him put on Lily Savage's Blankety Blank last night and he allowed it (only because there was nothing else on) and mumbled something about me coming from a very sad era. But I think perhaps it were a mistake as I started drooling over Lily's legs! (Strange to think that I grew up on Lily Savage, perhaps I thought her very hot in the way of an innoccent childs mind back in those days? Dunno)
But I noticed my man giving me looks. Was my cue to go and wash the dishes.
*Stop thinking of Lily Savages endless legs!*