Things are heating up in the divorce battle between Hilary Duff and Mike Comrie. The couple first announced their split in January 2014. Since then the exes have been spotted out and about together numerous times, giving fans hope for reconciliation. However, Duff officially filed for divorce in February 2015. A statement released by her rep claimed she and Comrie would “remain best friends,” although it appears that may not be the case.

Things between the once amicable exes seem to have taken a turn for the worst.  According to E! News, Comrie filed a response to his estranged wife’s divorce filing on April 16. The site was able to obtain those documents, which reveal that the former NHL star is planning to fight for joint custody of the 3-year-old son he and Duff share.

Duff’s initial filing reportedly asked that she be given primary legal and physical custody of Luca, while Comrie be granted rights to visitation. TMZ reports that the former “Lizzie McGuire” actress is concerned about her former hubby’s ability to parent. Sources say Duff believes Comrie parties too much to be there for the young child.

Comrie’s response acknowledges that the couple has a pre-nuptial agreement in place, which will help them sort out their property and spousal support agreement. Their son, however, does not appear to be mentioned in the agreement and may cause a rift between the pair.

The couple married nearly five years ago, in August 2010. The wedding took place in Santa Barbera, California. In an interview with Cosmopolitan Duff said she and Comrie were “very in love” when they first met and both felt they were ready to get married. Looking back, she told the magazine it may have been a mistake to get married so young, but added that they “spent the majority of our time together really happy.”

“It wasn’t working well enough to stay together, but there was still a lot of love involved,” she said. “It was just a slow set-in of us not being the match that we used to be. I’m lucky for the person he is and I am, and how we decided to handle this.”

Neither Duff nor Comrie have addressed their divorce or how they plan to proceed.