Can my ex-partner claim half of the child benefit if the child rarely stays there?

Questioner

My ex and I have been divorced for 11 years. He has never paid child support because it is in the parenting plan. No problem. He had the word co-parenting put in the parenting plan so he could claim half of the child support. Now he has 1 child of 16 years old week by week, who is registered with him. He gets child-related budget for that and he also gets child benefit for this child. No more than right. My youngest of 15 lives with me and is with his father at most 4 weeks a year. My child has very little need to go there. I get child-related budget for that and also child benefit. Now I already know that as soon as my oldest son turns 18, my ex will want half of the child benefit because he supposedly has 'joint custody'. Co-parenting actually only exists on paper. Completely contested divorce. Now my question is: Can my ex claim half of the child benefit, since my child rarely stays there?

Lawyer

Your ex cannot claim half of the child benefit.