I haven't ever asked my SO to do it before. I prefer sex to eating out, so I'd just make him go again if I hadn't gotten off yet as opposed to eating me out. But I have pulled his dick out of me and licked it in the middle of sex and I was very into that. Or he'll wet his fingers in me and I'll lick them.
But girls taste good, IMO.
And I must say on a side note: that threesome story way back up there got me all tingly!!