<human>: Can you condense the text into three sentences or less?

Boyfriend (m24) and I (f22) have been together for about 4 years. I think has been emailing other women through Craigslist and dating websites because that's how he said he likes to masturbate. Because it feels more 'real'. I saw his OkCupid account two years into our relationship, this has been deleted, but he was still messaging another woman on there too. I forbade it, because I considered it cheating. I have also been on his phone and have seen nude photos from other women. I'm not sure if he is still doing this, but I have a hard time trusting him still after all of this.

 He has also traveled to other cities and I've seen him looking on personals in that same city. He was using my laptop at the time, and was signed into my account so I saw everything on my browser history on my phone. I'm not sure if he cheated on me because he said this is how he likes to get off. The last time I confronted him about this he said that this isn't the way he wants to live his life, and stopped what he was doing.

If he was willing to lie to me about this before, then I am afraid he might do it again. He is a wonderful partner besides all of this and I want to know how to go about this and talk to him. He knows that I know everything, but I just want him to tell me the truth of he did cheat. Or if this is considered cheating. Fuck, I don't know anymore...
<bot>: Boyfriend knows likes to masturbate using Craigslist and has done this for the past three years against my wishes. I would've never found out about this if I hadn't discovered the emails, photos, etc. What next?.