Boyfriend is still active on dating site?

So my boyfriend and I met on this dating site about a month and a half ago, and since then things have been going great. I actually hadn't signed back onto mine since we started talking/going out, until today when I randomly decided that I was going to close my account down since I honestly didn't see a reason to keep it open anymore. But that was when I noticed that he still had his open, and apparently was still active, he'd been on it the day before. Now this bothers me for a number of reasons. We're exclusive, we have each other's relationship statuses displayed on our Facebooks, we've met the majority of each others' friends, he's introduced me to all of the people that he works with and talks about me a lot, and I'm meeting his family this weekend. (They're from out of state and are coming down to visit.) He doesn't seem like the type to cheat or screw around and if he's telling all of these people who are important to him about me then I doubt he would have someone else on the side. But it still is a red flag to me and I don't know how to bring it up without sounding like a crazy stalker! I'd like for us both to close our accounts since we're exclusive, but again, I don't know how to ask this.

This is one of the tricky and awkward parts about online dating. You can see when someone else logged in. I always felt awkward going back on the dating site after I had a good date with someone and I have to admit being on the other end it does sting if you have a great date and then see the other person logged on an hour after. 

That said it sounds like you two had a discussion and were exclusive so this is definately wrong. You definately need to call him out on it. I don't mean but it sounds like maybe he likes you and likes having you around but is still seeking someone else and may leave you when he finds them.

You definately need to call him out on this and see what he says and go from there. I wish you the best of luck you sound like a lovely young lady.