JoJo is engaged! The 31-year-old singer took to Instagram Saturday to share that her boyfriend, reboot actor, Dexter Darden, popped the question while the couple were on vacation, earlier this month.In the sweet post, JoJo revealed that Darden had flown out both their mothers and best friends for the surprise proposal, which took place during JoJo's birthday celebration on Dec. 20.«Forever with YOU? Sign me UP.