Sometimes having an open marriage includes having group sex with other married couples.
Open marriages always try to base their relationship on complete honesty and mutual respect. Open marriages are hard work and both partners must feel comfortable with the situation for it to able to work. Both partners involved in the primary relationship must be very mature and able to control jealousy.
Wilma starts fucking Gilbert and tells Joe. Joe gets turned on sometimes and jumps in bed with them. Joe in the meantime is also seeing Pablita and Maria and fucks them on a pretty regular basis.
Joe and Wilma have an Open Marriage.