Failure to exercise substantial overnight visitation is ground for retroactively modifying child support.
"[A] parent's subsequent failure to actually exercise the amount of overnight visitation that has been ordered is grounds for retroactively modifying the adjusted support. § 61.30(11)(c); Keeley v. Keeley, 899 So. 2d 387 (Fla. 2d DCA 2005)." Smith v. Smith.