<human>: Reddit, I need some advice.  I've been dating my girlfriend [22] for a little over a year.  We've had our ups and downs but it seems like the hard times have only made us closer.  One problem - we don't have sex.  Never.  Not like once a week, or month.  I bet it's been a few months at least since we've had sex.  Which I guess wouldn't be such a big deal if when we'd first started dating seriously she essentially explained to me that she loved sex and had a higher sex drive than most guys.  Is it normal for that to just … go away?

I'll admit, I have been slightly worried at times that she's cheating on me - but due to living arrangements and other circumstances I just don't see that it's likely to be happening.  I confronted her about why we don't have sex anymore on multiple occasions and I specifically brought up the fact that she was basically a self-proclaimed nympho when we first started seeing each other, but she couldn't explain why she was no longer interested in having sex.  I feel like somehow I'm the one at fault here, and I also feel like it's a waste of time for both of us to continue on in this relationship if things aren't going to ever get back to normal.  Should I stick things out and hope this is just a "phase"?  Or is this a sign that our relationship has become boring to her?

Give me a shortened version of the text
<bot>: Girlfriend used to be a nympho, now we don't have sex at all - is this a sign our relationship is doomed to fail?