Boyfriend is browsing dating sites?

My boyfriend and i have been dating about 6 1/2 months. About 4 months in, my boyfriend thought we were going to break up because of some unspoken tension. We worked it out but during the few days we hadn't mentioned anything about our problem he spent some time updating an old dating profile and searching dating profiles too. Recently, like the last two weeks i noticed that that he has visited the same dating site as before, not for very long it seems, just viewing a few people and than done. I brought it up before how i felt like it was wrong to be browsing dating site while ina relationship. And we worked past it however, im not sure what to do this time. He reured me before that he wasn't talking to people or making contact in anyway. but instead browsing out of curiousity and boredom because he still gets emails telling him of new matches. His profile isn't viewable to the public now, but he still has an account. Should i let this go? I feel like things are great between us right now and i don't want to rock the boat if i don't have to. But i don't want to miss something obvious either. Any Advice?