Sexist much?

In my Adult Development & Aging class today we discussed sexuality amongst the elderly. Not something you really want to think about, right?!? The textbook talked about how sex decreases later in life for women because they have a harder time finding willing and appropriate partners (after their husband dies, divorce, etc.), but then it talked about how men have a hard time finding willing partners. I thought that was kind of odd. Why do the men's partners just have to be willing and not appropriate? It makes me think of dirty, old men prowling for young girls or something. But then I thought about it again and it was kind of funny because it made it sound like old men have a hard time finding anyone who's willing, so they just take what they can get.