He says he wants exclusivity but you don't believe him

A statement like "I'm not really seeing anyone else" is a claim about the present. Your doubt usually comes from something that doesn't fit, such as long gaps in contact after a warm conversation, plans that keep getting pushed, or a vague answer when you ask what he's been up to. Write down the specific things that make you hesitate, because a general feeling of distrust is hard to act on and easy to talk yourself out of.

Sort those observations into two piles. Some are about availability and effort, like how often he initiates or whether he makes concrete plans. Others are about things you saw or heard secondhand. The first pile tells you how much room he's giving the relationship. The second is less reliable and shouldn't carry the same weight unless he confirms it. Keeping them separate stops you from building a case you then have to defend.

A reply that asks "do you really mean that?" invites a yes and nothing more. Better is a question about something concrete: how he wants to spend the next few weekends, whether he's comfortable being introduced to people in his life, or what he'd want you to know if he were seeing someone else. The aim is to hear how he describes his life, not to catch him out.

Be clear with yourself about what you'd accept as a good answer before you send anything. If you ask about weekend plans and he gives a specific, unhurried answer that includes you, that's a meaningful signal. If he deflects, goes vague, or turns the question into a fight about trust, that tells you something too. Going in without a sense of what you're listening for makes it easy to hear whatever you already expected.

If you've had the conversation and he's said the right things, the next step is watching what happens over the following week or two. Consistent follow-through, like making plans and keeping them, replying at reasonable times, and being present when you're together, counts for more than another reassurance. One good week doesn't settle things, but a pattern of follow-through does.

If he gets defensive or vanishes after you ask a direct question, don't chase him with more messages to get the answer you wanted. Send one clear follow-up later if needed, and then let his response stand. Continuing to press after a clear non-answer usually just gives you more reasons to doubt him and fewer ways to feel steady.