It's not even Spanglish, it's a television invention they use on a reality show to name a sexual relationship that is practiced under a duvet. The goal is for the situation to be clearly interpreted on camera, but not to violate the morality standards for the TV show. See big brother .
EDREDONING action of manufacturing or covering a bed with a duvet, in Spain and Mexico, piece of fabric padded by a filling of bird feather, synthetic fiber or other material, and covering the bed.