Kelly Ripa and her husband Mark Consuelos celebrated a major family milestone this week when their youngest child, 18-year-old Joaquin, headed off to his high school prom.The couple proudly posted snapshots on their Instagram accounts, showing their son with his prom date Melissa – and Kelly also shared a touching detail ahead of the big event.MORE: Kelly Ripa shares intimate bedroom throwback photo WATCH: Kelly Ripa shares video montage for son's 18th birthdayAfter Mark uploaded his photo of