I've been dating this guy (let's call him Daniel) for about 8 months. Daniel is a really nice person and a lot of people tell me how great we go together. We've never gotten into an argument. I genuinely like hanging out with him. The problem is that I'm just not sexually attracted to him anymore. We used to have sex all the time but in the past two months we've only had sex twice (and both times I wasn't really feeling it). Daniel is such a nice guy that he hasn't even mentioned to me how drastically different our sex life is now vs 8 months ago.

How do I let this guy down gently? Is saying "You're a great guy but I just don't feel sexually attracted to you anymore" good enough? Pretty much all my other boyfriends I've had to break up with were jerks and so I didn't mind being curt. It's not that I really want to be friends with Daniel (at least right now). I just don't want to completely break his heart and come off as an asshole. (Also we have a Phys Ed class together, so we'll have to see each other twice a week.)