trying not to get frustrated

So, today is Saturday and I wanted a little break from the kids like a couple hours. So, i asked my husband if he would take them to the park and he said "why don't you want to come wsith us" and I said "Because I'm tired". So, then they were on their way out the door and I gave Brad a bag with their stuff in it and he was acting miffed so I said "are you mad" and he said that he didn't understand he wanted to do something together and then I jsut started crying. I feel like sometimes he just doesn't understand how taxing the kids can be on me and I just want to be in the house by myself to do whatever I want to do. So, he took them down to the park riding their scooters. Well they were back in aboutr 15 minutes and Katelyn had poo-pooed her panties and he was mad. All I could think was welcome to my world, then when they were going to go back outside he said to Katelyn "you have to stay here with mommy" and Katelyn was crying and he said "well you should have thought about that before you poo-pooed in your undies as soon as we got down to the park and walked out the door with Alex. Well that made me upset because he gets upset when I do that with the kids because he doesn't want me to yell at them, so it's okay for him to yell at them? I felt bad for Katelyn even though she should not be going #2 in her pants she can't be expected to never accidents. I'm just trying not to be frustrated at him.