Upside-down pineapple has been associated with the swinger community as a symbol or signal. The idea was that if someone had an upside-down pineapple displayed in their shopping cart or outside their home, it indicated they were open to engaging in swinging activities. However, it's important to note that this association is based on urban legends and rumors, and there is no widely accepted or definitive connection between upside-down pineapples and the swinger lifestyle. It's always best to communicate openly and directly with others when discussing personal preferences or interests.