No, the second word isn't a plural. Think of a well-known senator Bob ????. The first initial is one of the red suits in a pack of cards so you need to change it for the other suit (initial only).
For the first word, it's quite straightforward - think of an American word for a season (I think there is only one that differs from our words) plus a word meaning to go nude in public. You will probably not have heard of the answer, so google it.