My bf is bi curious.

I recently found out that my boyfriend of two years looks at the posts​ on the Craigslist personal section Casual Encounters w4m AND m4m. Also, I couldn't help it after seeing an email saying "bottom boy looking for dick", looked closer into his personal emails and found that in the past he's hooked up with men and women that way. I confronted him about it, and he admitted to doing it in the past, but the present emails he said he would never act on them...he just gets curious about what's in the area after watching porn. He "has never, and would never cheat on me". This is my first time expressing this to anyone other than myself. Confused, hurt, I love him, want to believe him...and so far he has been true to his word as far as I can tell. ...thoughts?