The upcoming divorce of rocker Pete Wentz and pop star/actress Ashlee Simpson is heating up, and looks like it could get dirty. The couple split last month, with Ashlee filing for divorce and asked for primary physical custody of their two-year-old son, Bronx.

On Tuesday, Pete filed papers requesting joint physical and legal custody of the boy. Ashlee also asked the court to send Pete the bill for both sides, but he wants each of them to pay their own legal fees. This breakup seemed fairly amicable when it was announced, but these things have a way of turning ugly when children and money are involved.

Ashlee’s singing career was already on the downslide when she wed Pete shortly after becoming pregnant with his baby. She hasn’t done much during the marriage except for a short-lived stint on The CW’s revival of “Melrose Place,” so most of the money earned while the pair was joined in matrimony would be from Pete’s’ musical career.

There have been rumors that Ashlee was the one who wanted out of the relationship, and that her soon-to-be-ex hubby wasn’t happy about the split. Maybe he’s had time to rethink the whole thing and decided that his ex can talk a walk, but she’s not taking his kid and a big chunk of his cash with her.