He has admitted to 2 affairs, both with co-workers. He's given more info on the most recent one but almost no info on the first affair which occurred sporadically over several years, anywhere from 2007 to 2012. I discovered the most recent affair & confronted him. He confessed to the original affair about a week later. He continued to lie about many things, such as whether he said he loved them, having sex in his office, exchanging videos, never volunteering these details but only admitting under interrogation. When I ask him for specifics he says he doesn't remember. He claims he doesn't remember the timeline for the first affair, the number of times he had sex with either of them, what he told them about me, the plans he discussed with them, what they said they wanted from him. Additionally, judging from physical evidence that I now realize occurred only when he was unfaithful, I believe there are either others or his affairs were more involved & lengthier than he is admitting. Also during a heated discussion he did grab me by the wrists, look me in the eye & declare "I'm a serial cheater" then walked it back when I pressed him for what that meant. I believe this was his way of "confessing" without actually confessing, as he tried that tactic on D-day by just saying "I'm an adulterer" and wanting me to fill in the blank & move on without further questioning. My question is, if he doesn't come fully clean can he ever be truly safe to continue with? Also, in the event I do discover that he is a serial cheater with many more APs, can someone like that truly change & be safe?