My evidence is not directly empirical (I'm a straight chick), but based on anecdotal evidence from my sisters and my friends, I'd apply the one-thirds rule here, i.e.:
one third of women love receiving oral sex to the point that they prefer it to other forms of pleasure.
one third of women enjoy it, but have no real preference.
one third of women dislike it.
Personally, I enjoy it if the guy is orally talented, but can't stand it if the guy has no idea what he's doing and goes after my clit like he's eating a buffalo wing. I once was subjected to guy who promised to make me cum with just his mouth --his technique was strictly limited to thrusting his tongue in and out of me. Even then he had no sense of rhythm. I tried to show him some tricks, but he got angry and told me I was a freak because it always made other girls cum.
If your wife is willing to let you do it as much as you want, you're a lucky man.
Why don't you just stick your head down the hole in a port a potty, same results.
