Whew - lots of comments.
In no particular order: Lubrication isn’t a problem; she is as wet as they come. Like I said earlier, it’s not that she doesn’t like sex: She enjoys the sex we have. She initiates sex, and she comes almost every time, and I’m pretty sure she’s not faking (guys, most of you probably have experienced what the vaginal walls feel like when a girl reaches climax; pretty hard to fake that!).
I’m late 30s, she’s early 30s.
About twice a year we try oral sex (both ways); she just doesn’t like it. Ditto various positions. We’ve tried numerous - even when it isn’t painful, she just doesn’t like being on top or doggie style. She’s generally not willing to do something she doesn’t want to do (she’s very strong willed - one of the things I love about her), but that’s beside the point because having her do something I know she doesn’t want to even try is a mood-breaker for me.
The sex is bland, but I wouldn’t say it’s bad. Basically it’s 30-40 minutes of foreplay (lots of touching, rubbing, and kissing) and 10-15 minutes of insertion, sometimes followed by a handjob. 2-3 times a week. I know lots of couples that would kill for that kind of sex life 
I’ve heard her talking with girlfriends about it - they all tell her she’s crazy for at least not wanting oral, and one friend keeps getting mad at her (jokingly, of course) for not giving BJs; she’s (jokingly, I think) offered to ‘help out’ :eek:
But she tells them pretty much the same thing she tells me - she doesn’t like something, and why should she do something she doesn’t like? Plus, she’s very happy with me in bed, and she doesn’t ‘want more’. The fact that I want more doesn’t factor into the equation, and it’s the ONLY aspect of our relationship where I feel like she is being selfish.
Am I with her because I couldn’t do better? Almost all my ex gfs were better in bed. None, and I mean none, were as good of person and gf as she is in every other aspect of the relationship. She’s beautiful, intelligent, has a very respected career at a very very well-known, respected institution, had her master’s at 23, speaks three languages, and has essentially zero emotional issues (other than sex, which may or may not be related to emotional issues). I long wondered if there wasn’t an abusive history involved, but I’ve pretty much ruled it out by now: she initiates sex, she clearly enjoys it, and she is very self confident about herself and about her appearence.
I haven’t thought about cheating (well, ok - the friend offering to help out has introduced fantasies of a three-way
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