What should I do?

So my SO bought tickets to a paint party a few hours away from home for tonight. I am out of town taking care of my gma because she broke her leg and can't be home alone. He hasn't mentioned it to me. I know he's sleeping now but I feel like this is something he needs to tell or at least discuss because partying isn't in our budget right now! I plan on asking him about what he's doing today/tonight and if he lies I'm going to show up at the club...am I wrong to do that? Is that the right move? I'm so upset I can't sleep I've been up since 2:30am just debating and trying to figure out if I need to be worried or not