They should have had a different way of doing that. They didn't have a huge fight when he went to investigate the DiMera's that time when he was working for them. There is no way she would have gotten pissed off that much that he went to work for the ISA. She may not have liked it, but she would have supported him. They could have easily written it where he joined the ISA, and traveling a lot, but they still talk everyday.