TMZ has learned ... the woman was around 13 when she babysat Collins' daughter 18 years ago. Collins' wife, Faye Grant, told cops Collins admitted to her he would repeatedly drive with the babysitter in the front seat with their 6-year-old daughter in the back seat and expose his penis to the babysitter.
Grant says Collins tried making excuses, saying the babysitter didn't see his penis when he exposed it and his daughter didn't see it either.
Cops want to talk to the woman. So far, they haven't made contact.