This is one of those times we don't need to err on the side of caution. He has Sash and Ari's staying the next few days. Sammy's a couple of blocks away, his doctors can be reached on-call. This is a mother and son thing you need to do, love. It's important to him. He's already worried we're both going to pull out. If you cancel out on him, he won't put it down to a mere errand. And you've got to want him there with you, right? You invited him in the first place.