'Teen Mom' Maci Bookout -- When The Baby's Away ... Mama Parties Her Face Off!!

Former "Teen Mom" star Maci Bookout had a momcation in Miami this week ... and with no kid to look after, the 22-year-old let everyone know it was BOOZIN' TIME!!!

Sportin' a shirt that read, "Off Duty," Bookout was seen smokin' ciggies, drinking beer and even swiggin' a champagne cocktail on the beach.

Bookout also posted video of a dancing session in her hotel ... good times.

Of course, Bookout has a 5-year-old son Bentley, but he was reportedly at home with his father Ryan Edwards.