Apart from the ridiculousness of this whole situation....if you do want to keep having access to your stepson, make sure it is all spelled out legally, and dont rely on good will.

My ex assured me I would always have access to my daughter, and even though I have all the legal court documents assuring me acces, I still havnt seen my daughter in 4 years :(

(because she is now 16 and the police cannot "force" her to go against her mothers wishes shrug)

Divorce is never fun....just make sure you keep yourself covered.