If you want my story, it's pretty similar (except I'm the girl).
High school boyfriend, first love, first kiss, etc. We're both religious and we planned on getting married before going any further physically. We were together for four years. We went to college together.
Over the course of those four years, I was working a lot. He never worked. At all. Finally, he got a job after I talked to him about how we cannot have a future together if he's not contributing. He got a job, but quit after a few weeks. Ultimately...this caused me to lose respect for him. There were other things, too. He let his appearance go. He never fixed himself up, and he started gaining a lot of weight. Started to even get a bit of a potbelly. He had a back condition that required him to do exercises to improve posture/stability, and he stopped doing them. He would neglect his car.
Ultimately, the time came where I knew he wanted to propose. So I broke it off. I didn't want the future with him that he was offering me. Why would I want someone that was not motivated, that neglected everything?
It's been three years since then. We had coffee together the other day, and talked. We both have new significant others now. Every so often, we catch up. We're friends, but we're never going to be in a relationship again.