No, it used to be a regular thing. She has not let me go down on her since our first child was born 5.5 years ago. I would be happy to do it at a moment's notice, though. The last time she did it for me was last year on my birthday, roughly 13 months ago. The thing is, that was the last time I asked. She might be willing to do it again, but I have not asked. She has not offered, and I just can't seem to find the words to bring it up. How can I say it in a way that isn't "I know you work part-time, go to college full time, and raise 2 kids, but could you also please put my **** in your mouth?"
I'm quite sure she used to really be into sex before the kids. She used to buy lingerie, have orgasms on a regular basis (I know she didn't fake them all), make me have sex with her in risky public places, etc. It's like she doesn't even remember that she used to be that way.
I take her out on dates, maybe once a month, but overnight babysitters are hard to come by. She's so worn out, and if we have an overnight babysitter, I know she'd rather get a full night's sleep than stay up having sex with me all night.
My situation isn't exactly like yours, but the sex aspect is. Things were great when we were dating, went downhill after the first kid and have just about tapered off after the second. She just dropped the bomb on me one day that she's never desired sex. She only did it because she wanted kids. She feels it has no purpose now. Like you, it has become duty sex. She does it so I can get off but there is no passion behind it anymore. It's "get hard and get done". I've tried explaining that it's not about the getting off but about that connection/intimacy.