Three men are sitting in bar.  All of them are clearly drunk.  
The first one says: "My wife is so reluctant to give me oral sex; if she does it once a week, I'm thankful."
The second one says: "You're lucky.  If mine gives me oral sex once a month, I feel like she's doing me a big favor."
The third one says: "You're both luckier than I am.  Mine always refuses.  If she didn't sleep with her mouth open, I'd never get any oral sex."