We need to have married couple time

I am going to need to get some wrinkle remover, with all the stress dad has been putting me through. Last night hubby and I decided we would go out with a friend, and share with her some of our struggles as a married couple who took in dad. We had a great time and were able to share things, and well this meeting was a lot less tense and went smoother, probably because hubby and I are getting along pretty well.
I got home afterward and dad was just in a real fowl mood, he was made and accused me of lying to him about what hubby and I was doing, and that we was doing something to make him not involved with problems. Well nope we went out to have a good time, and not have dad baby sitting us. I just do not understand how he can be so angry because hubby and I take one night a week to us and we are not out late and sometimes we meet up with other friends.
To make things harder he is simply confused and getting dreams mixed up but goodness forget about telling him he was dreaming and it never happened because he will not listen to reason. It kind of frustrating to come home and be yelled at, and deal with his bad attitude and grumpy mood everyday. I try hard to make sure he gets what he needs and wants but some days it very hard to be around him.