What to say when ex says he misses you but

The first half of the sentence is an emotion he's allowed to feel and mention without consequences. The second half is the constraint. When someone says they miss you and then immediately explains why nothing can happen, the "but" is almost always the honest part. It usually means he's not leaving his current situation, he wants a connection without the obligations that come with it, or he's testing whether you'll still be available if he's not ready yet. Any of those can be true at once, and you don't need to know which one to respond well.

What matters is the pattern around the message. Has he contacted you only when he's lonely, bored, or between relationships? Does he disappear again after a few days? A single message is information. A repeated cycle of miss you, then nothing, then miss you again is a clear answer about how he's using you, even if he doesn't mean it that way.

There are roughly three kinds of reply that fit this message. One acknowledges the feeling briefly and names the limit back to him, for example saying you hear the missing and you hear the not ready, then leaving it there. A second is a clear no to the friendship-with-benefits version, where you say you're not interested in staying in touch while he works out what he wants. A third is a door that stays shut for now, where you tell him you're glad he reached out and that you'll see how you feel later, without promising anything.

You can tell a draft is the right kind when it names the "but" in some form and doesn't ask him to explain or defend it. It should leave out any question about whether he's seeing someone, any reminder of what you both used to have, and any hint that you'd be happy to pick up where you left off if he changed his mind. Keep it short. The shape is: acknowledge, name the limit, stop.

Send your reply the next day, not while he's still in the mood and you're still reading the message over and over. A calm reply sent a few hours later reads as settled, and a fast one reads as hungry, even if the words are identical. If he answers with more of the same miss you, don't match the energy. One follow-up is fair, usually if he asks for clarity. If he pushes for a call or a meetup to talk it through, that's a sign the "but" is about to get dropped, so decline and stay on the boundary you set.

If he goes silent after your reply, leave it alone. Silence is an acceptable outcome. If he comes back in a month with another miss you, you can decide again from scratch rather than assuming the last conversation is still open. Stop the conversation when it starts repeating itself, because a third round of the same message is not new information.