Hi Carly, I don’t claim to have a resolution for your situation, mainly because I can’t possibly know everything that’s involved.

Though I think I can offer some insight.

Based on what you’ve said, I see one glaring issue. Your BF was with his ex and you during a same time period. Can I assume that the ex did not know about this relationship with you during this time? That he was cheating on her with you?

If it was cheating, then you know without a doubt that he has cheated in a relationship. Not to mention that you have stated that you have cheated in a relationship as well. It would not surprise me if this is the reason (or at least a main one) for your being suspicious of his intentions.

Let’s say he never sees his ex again. Ask yourself if you’re still suspicious of him in other situations. While you’re at it, ask yourself if you trust yourself in other situations as well. You may be at a point in your life where it’s a good idea to take a step back and evaluate what kind of romantic relationship you want to have. Do you want a relationship where you don’t have to worry about him sleeping with someone behind your back?

If you routinely have these feelings about him cheating, I have to say it would do you well to take a step back and consider these things. How much of a step back you need is only for you to measure. Maybe take a few days to yourself. Tell him this, rather than disappear from him. Communication is the key. If he doesn’t like the idea of you taking some space for yourself, then ask yourself if you want to be with someone who doesn’t allow you your own space.

My point is that each of us is free to pursue the kind of relationships which we feel comfortable with. This does not mean attempting to change the other person. Though it may mean changing yourself, in the ways you see fit. You set your own standards/boundaries, though it may take some time to work those things out on your own, discover what those are.

Accept the possibility that things might not work out between you two. I can tell you really don’t want the relationship to end, and yeah it’s a heart breaking experience. But it’s not the end, and you know it.

Hope this offers you a new and beneficial perspective.