<human>: Can you provide a brief rundown of the text in within 3 sentences?

We got together in college - my first long term relationship. He is the first/only person I've slept with. We've been together 10+ years (married for a few of those) but I think I stayed with him because I love him as a best friend and as a person, but not as a lover/husband. 

He's generally a great guy (no abuse, no cheating) but there's no spark from my end and there hasn't been in a long, long while. Our interests are similar but they've drifted more and more apart over the years. It's a lot of me trying to get him to do things that he says he likes but won't actually initiate. 

I don't look forward to having sex (despite a lot of effort on both our parts to help this for the past 1-2 years). And now little things are starting to drive me nuts. I'm feeling trapped and I don't want to think about kids with this person if this is how I feel. 

I thought this might just be what happened in a relationship when you've been together a while but I also suspect that I should have explored more before committing. I found someone who seemed like the 'nice guy' and a 'good guy' but I don't think he's the right husband. 

This has been brewing for a year or more and it was really pushed forward by the fact that I just reconnected with an old friend who admitted a crush on me. Just talking to this guy makes me knees weak - I had no idea what that meant before him. I'm well aware that I can't break off my marriage for this random other guy where things might or might not work out in the future - it's just a currently complicating matter. I was beginning to feel like I'd never *feel anything* for anyone again.

Is it terrible to leave a marriage for the reasons above? Is this a dumb choice? The idea of being single makes me feel excited/hopeful. I feel like a really terrible person.
<bot>: I think I've fallen out of love with my husband but I don't know if that's a good enough reason to end the marriage