<human>: Could you distill the essence of the text into 1-3 sentences?

First time poster, hope this makes sense. I've been with my boyfriend for 2.5 years and I'm starting to feel trapped/ like the relationship is coming to its natural end. We got together straight out of school and since then it feels like I have changed and matured, but he is the same. He still has a bunk bed in his room, doesn't deal with paying bills and is uncomfortable going out to bars or staying up late. He is afraid to rock the boat or change anything at his casual job, whereas I have worked four jobs already this year. 

The sex is stale, which is definitely partly my fault. I have a hard time getting turned on by him and have to really psyche myself up for us to have sex, so trying new things is more than I can handle right now. Worse, I'm not sure if I WANT to get our sex life back on track... 

I keep thinking we should break up, but he doesn't seem to be on the same page at all. In his head everything is fine and he still wants me as much as ever, meanwhile I don't miss him at all when we aren't together. So should I break his heart? He is a genuinely lovely person, has never hurt me and is incredibly reliable. I think I'm just too young and need to branch out, but I'm worried I'm throwing away something very valuable. Advice much appreciated!
<bot>: My boyfriend of 2.5 years doesn't do anything wrong, but I'm just not feeling it anymore. How can I break his heart?