Charlie Sheen fights for custody of his children as Brooke Mueller enters rehab (Creative Commons)

Charlie Sheen is going back to court Tuesday, demanding he get full custody of his 2-year-old twin boys Max and Bob, after his estranged wife Brooke Mueller refused to a random drug test on Friday according to TMZ.

He also wants to stop paying her $55,000 a month in child support, which he has been paying ever since their first custody settlement. Mark Gross, Sheen’s lawyer, intends to ask in Tuesday's court session that Mueller be stripped of her legal and physical rights to care for their children after checking back into rehab this weekend. Sheen’s team will also use the fact that Mueller refused to submit to her required drug tests on Friday as further evidence of her inability to care for the twins.

Gross gave Mueller’s attorneys notice earlier today, letting them know that they’re asking for full custody. Mueller’s lawyers in turn announced that they are already planning on their own to defend Muller, asking that Mueller retain full custody, and that Sheen be psychologically evaluated.

But after TMZ reported that Mueller was back in rehab after a series of erratic and bizarre behavior and an alleged drug binge last week, including trying to pawn a stereo and a watch that may or may not have been Sheen’s, Sheen might look like a safer option for his children.

Mueller shows no monetary need to pawn these items, which she took to a pawn shop in Inglewood, as she already receives regular child support and was awarded a substantial amount of money from her settlement with Sheen. The actor, despite his weird and raving antics, has been clean since his rehabilitation at home earlier this year.

Mueller refused to take a random drug test Friday, which both she and Sheen are required to do under the conditions of their existing custody agreement. She has currently left the twins in the care of her mother.

Mueller is no stranger to rehab, as she entered The Canyon rehab center in Malibu in February 2010, where she was treated for both drug and alcohol abuse. She checked into a facility over the weekend for her latest stint in rehab. 

The pair’s divorce is still pending and is expected to be finalized sometime in May.

Reach Staff Reporter Kristin Yinger here. Follow her on Twitter here.