Parents Night Out.
If you have some older Youth, Teens preferably, have them advertise to the congregation, that one night that you designate, they will babysit the younger children, ofcourse you and the youth staff would be present, it consist of them bringing their children to the church fellowship hall or somewhere like that. The Teens would have games and activities, to keep the children busy, while mom and dad have a romantic evening, you could charge a fee and accept donations.