Marc Anthony's being a bugaboo!

Although he and Jennifer Lopez announced their separation nearly a month ago, the singer's still not ready to let go, a source tells Us Weekly.

"He calls her nonstop, especially when he's drinking," the insider says. "Marc is constantly harassing her and doesn't think she'll go through with the divorce."

(Anthony's rep denies the calls, and the twosome put on a united front in Southhampton, NY August 10, so Anthony could spend time with 3-year-old twins Max and Emme.)

Get more info on continued fallout from their messy split and more in this week's Hot Stuff video, hosted by Us' Senior Editor Ian Drew.

Also in the roundup: Jennifer Love Hewitt's "awkward" makeout with Bachelorettte star Ben F, more on Sandra Bullock's estrangement from her former stepdaughter and more.

Watch the clip now!