If my boyfriend is a registered sex offender could I lose custody of my kids if I bring him around the kids? My ex threatened to take custody of his daughter if I ever brought him around so I have not. I have known him for years and know he is no threat to my children. He was 19 when it happened and a minor under the age of 16 lied about her age and her father found out and had him arrested. Now he's stuck registering and is categorized as a sex offender. Is there anything I can do or will the courts side with my ex husband?