The strangest thing about the Anthony Wiener fiasco?

Obviously, a lot has been said about this, but here's something I can't figure out. Why would he use his "official" Twitter account to communicate with his girlfriends? This just makes no sense to me. I'm not condoning what he did, obviously, but, hypothetically, if you were going to have an online affair, or multiple online affairs, as seems to be the case here, don't you think that you would create separate accounts to communicate with your mistresses? I'm not saying he wouldn't have gotten caught eventually, but for him to do this over his official Congressional Twitter account (that plenty of media/political types would be following) is bizarre to me.