What can my exh really do?


my exhusband and i have 2 kids together, he has adultry and substance abuse in his past and now lives with his parents to"try" to straighten up.we have been separated for over a year. we have an m.s.a. signed and noterized between eachother, it has been in efect for 3 months. he has said over and over again that he doesn’t want the kids, but now he wants to have the kids everyother weekend signed into the msa over the fact that he signed the kids to me. in the msa it says that based on his behavior( verbal behavior or harrassment) he isn’t suppossed to see the little kids we had together. are his threats valid, can he or anyone changed what is in the msa?