If you want to get him on your side, you'll have to drop the fighting words and instead use language he'll be able to hear. Let him know that you understand that, to him, "it's like porn." You could therefore agree that it's not cheating. (Trust me, I barely got through that sentence without cringing. Ground-ceding is the worst, but it works for a good reason: It lets the other person know that he or she has been heard and understood. Even if you're diametrically opposed, this is a powerful gesture, and it enables the other party to lower defenses in turn.)

When you've totally laid that groundwork, then make your boyfriend understand what it's like on your side. You didn't anticipate this situation and how it would make you feel. You're not sure how to navigate it. You know it's not technically cheating, but it makes you feel all those same "cheated on" adjectives. So, it doesn't really matter what the verb is at this point. How are you going to address the adjectives?

Once everyone's on the same page about that, it's time to actually do something. In terms of actual behavior changes, I suspect you're both looking at some sort of compromise. Again, in an ideal world, he'd immediately stop following those accounts because he doesn't want to hurt you. But, again, if you've been wrestling with this issue for a while, you've got all that tension, hurt, and mistrust lingering in the air — and there's no quick fix for that.

Maybe he gives up the accounts you're most upset by. Maybe he limits his time on the app entirely, and you, in turn, agree to stop tacitly accusing him of cheating and instead stick to the adjectives when you need to talk about this. Compromising on the Instagram accounts might eventually mean he gives them up on his own. No promises there, but if he really understands how hurt you are by this behavior, he probably won't get the same enjoyment from those accounts going forward. However, if he feels like you're making unfair accusations and trying to control him, well, that might make the forbidden fruit even more tempting. That's not a guy thing, by the way. That's a human thing.

All this is based on the premise that your guy is a good guy and you think your relationship is worth all this negotiation. Before you launch into the big talk, I'd urge you to ask yourself: Is the Instagram thing part of a bigger problem? If so, you might need to do a lot of big-talk-ing. The good news is that successfully dealing with one problem in a compassionate, adult way makes it much easier to deal with the next problem that way. And if you're in this thing for the long haul, this is just the first of many problems. Maybe that's the wrong word. Disputes? Complications? Either way, you're going to face some tough shit, so you might as well learn how to face it together.