I want to know the reason for a joke in Friends.

I remember that they were talking about where to have sex (though it shouldn't be specified) which made them feel the strangest. When Rachel said the foot of the bed, she meant it was beside the bed, but it was still on the bed. Then everyone paused and thought she was the strangest. In fact, I think everyone is being sarcastic. It's not strange at all, but Rachel thinks this is a strange place, so she agrees. done ...

Some people think that because Rachel is usually an open (dissolute) person ... all the places where she often has sex are strange to everyone, but it is strange to her in bed. This is the reason why she is heckling. ...