I'm in the park this morning before meeting friends for lunch. I bought some ice cream and sat on a bench occupied by an old guy at the other end and in the middle a load of coat and bags. He told me "excuse me that's my wife's seat" (she had gone to get drinks). I told him he could move the coats when she came back. He did and there would have been room for another person as well as his missus.
They just didn't want to share the bench and muttered when they left about respect for your elders.