Im honestly and truly pissed!

I just want to scream from the top of my lungs till I have no voice. I've had plans made for over a week. My SO not only knew about the plans, but he was the one to tell me to go before I had even thought about going. I'm supposed to go tubbing today with old co-workers, we're like a mini family. My SO got back from a week long remodel last night. Still knowing about these plans he tells me he's going to go into work today for a while. Mind you he DOES NOT have to, it's Sunday so technically it's their day off. I also have family to visit while also picking up things people got for our son before I go tubbing. He knew I wanted to be out if the door by 10am. He doesn't plan on getting up till 11. So I went and asked him at 9am if he had still planned on going in. His reply was probably, but don't cancel your plans. The group of us are supposed to be meeting up at 2:30. So I guarantee that my plans are cancelled and my day is ruined. This would have been my first day without our son and having actual interaction with people that aren't my neighbors. My son will be 5 months Thursday.