Goes cold after closeness
A great weekend or a candid one-to-one, then days of short replies, sudden busyness, or talk only about logistics.
Rule out first
Actual workload. Introverted recovery after intensity. Something unrelated happening in their life.
What could explain it
Introversion and extraversion (Jung's original sense): They come back warm once recharged and can say so; the withdrawal is predictable and not hostile.
Deactivating strategies: Afterwards they play the closeness down ('it was fine'), stress their independence, and get irritated if you name the distance.
Fearful-avoidant attachment: Push and pull: they return as fast as they left, and closeness seems to frighten them as much as draw them.
Fusion versus intimacy: Closeness feels like losing themselves; on return they reassert opinions and space with some force.
Shame: It follows a disclosure; they avoid your eyes. The retreat is about feeling over-exposed, not about you.
A next move
Don't chase. Wait, then name it lightly: 'you seemed to need space after that.' Ease points to introversion; minimising to deactivation; embarrassment to shame; a quick swing back to fearful-avoidant.
If it’s you
What did I reveal, or feel, just before I wanted space?