Moody scorpio?? Or pulling away?

So I have a fantastic FWB, we've made plans all week to get to together(wink wink) and today he tells me, we'll do dinner and hang out. Now I think he is a great person and I do really like him as a friend and would love to just hang out and conversate. My issue is we have been teasing each other all week about what we'll do to each other and then, meh doesn't feel like it? I am little worried of two things; A: he is interested in starting the LTR( we both have been through the ringer lately have agreed not ready for that for a longtime) or B; he may be pulling away. I just wonder what the deal is, I will ask when I see him but any opinions?