He pulls away whenever we get close. What's that about?

Closeness followed by distance is a sequence you can describe. The sequence alone cannot establish fear of intimacy or an attachment style. The useful question is what kind of contact each of you wants after a close moment.

Naming that sequence gives him a chance to explain his experience while leaving yours intact. You do not have to stay perfectly warm or withhold affection to manage a feeling that has not even been established.