just found out my ex (my girls baby daddy) got engaged

Sh

this past weekend my girls came home excited to tell me their deadbeat (not paying child support) dad got engaged. after a long fight over who would get them for Christmas he decided he just wasn't going to pay child support. so this weekend my girls tell me he got engaged. so he bought his fiancee a ring and couldn't pay child support. my 12 year old is now fighting to live with her dad, the one who's seen her and her sister 10 weekends in the past year. I dont stop him from seeing them. he simply does not make time for them. the storey is far more complicated than that too. am I allowed to be angry? I've since been working on papers to file on court so I don't have to deal with him. Update: filed my papers with the courts yesterday and told him anything further to deal with my lawyer aka me, if I dont have to have contact with him I won't