What to do when a guy shows interest, then backs off?

One short message after a warm stretch is normal. A pattern of him being interested for a few days and then trailing off usually means his interest is real but unsteady, or that he's testing how much you're chasing. Look at what changed. Did he stop suggesting plans, or did he stop answering questions in full? Did his replies get shorter but still friendly, or did they get vague? If he still asks about your day and keeps the tone light, he's probably busy or unsure. If he's been checking out without any warmth, the interest has likely dropped.

Also look at what he did before he went quiet. If he had already made a plan and then backed off it, that's a stronger signal than a slow fade. Plans he proposed and then cancelled tell you more than the texts around them. Treat the change in his behaviour as the thing to read, and don't rely on the wording of any one message to explain it.

A reply that fits this situation is short, friendly and asks for nothing. Its job is to show you're easy to talk to and that the earlier plan or conversation still stands if he wants it. One kind of reply references something specific from the earlier chat and makes a low-stakes offer, so he can say yes without committing hard. Another kind simply reopens the thread with a question about something he cares about, with no mention of the gap. A third kind moves the plan forward on your terms but gives him an out. In each case, a draft is right when it reads like an ordinary text from someone who isn't keeping score. Leave out any mention of how long it's been, any question about his feelings, and any sentence that begins with a justification for why you're writing.

After a reply that gets no answer, give it three to five days before you do anything else. Sending another message within a day tells him you're waiting, and that usually pushes him further away. If the silence runs past that window, you can send one brief follow-up that is clearly lower stakes than the first, such as a casual question or a light comment on something you saw. If that also gets nothing, stop. Two unanswered messages after a pullback is a clear enough answer, and continuing to send more only shifts the imbalance onto you. If he does come back, match his energy. If he comes back with the same warmth, you can rebuild the plan. If he comes back cool, decide whether that's enough for you to keep going.