A little worried about bf

So my bf and I have been together for 9 months, a happy and loving 9 months. Just this weekend we hung out Friday and saturday, nothing out of the usual - but for some reason he didn't want to touch me those two days. Usually when we lie down later in the night to watch a movie we make out and stuff like that for most of the night. Last weekend, we had sex for the first time together and I thought it went pretty well-so its not like the intimacy is depleting-this just came out of the blue. So anyways, yesterday he wasn't acting too strange-but enough to make me worry. He still put his arm around me and he cuddled with me. However, he didn't put his hand on my butt or try to touch me in that way all night. I tried to muster up some courage to get him to kiss me, so I started kissing his neck, and he got into it for a bit but then he stopped and said he didn't want to kiss tonight. I agreed defeatedly and we went back to watching the movie. This just makes me worry cuz we've never gone a weekend without getting intimate; and he is usually the one that instigates it. Should I talk to him or let it slide?