<human>: My boyfriend tried to initiate sex and I told him I wasn't in the mood. As soon as I told him though, he completely shut down and has been ignoring me all day. He hasn't even gotten out of bed. This has never happened before and just wondering whats going on. I've asked him if everything is okay and he just responds with a half-assed "yeah." I know something is up just by his behavior. 

There have been times in our relationship where he has gotten upset and done this same behavior, but not because I wasn't in the mood and he wasn't. And the thing that's even more puzzling is that we had tickets (partially why I wasn't in the mood, we were running a little late) to go see one of his favorite comedians. He's been looking forward to this for weeks! It's actually one of his early Christmas gifts. And then all of a sudden on the morning of he doesn't want to go? This can't be just because I wasn't in the mood, can it?

Our sex life is normal in my opinion, although I have been busy these last weeks as the semester winds down. Our relationship doesn't have a specific start date. I would put it around summertime. I've known him since I was 18-years-old and we dated in 2010-2011. We were separated for three years and reconnected earlier this year. He is now living with me in my apartment and just yesterday moved into the room my old roommate moved out of this weekend. There have been times in the past were I wasn't up for sex and he was totally fine with it. Need some advice. How can I approach him and get him to tell me what is really going on?

Can you condense the text into three sentences or less?
<bot>: Wasn't in the mood for sex and told my boyfriend after he tried, hasn't talked to me all day and decided to skip out on plans he's been looking forward to for weeks.