Picking up child by the head?

When they are playing, my husband picks up our 3.5 year old son by the head. As in he puts his hands on the sides of his face, lifts his whole body up and dangles (edit: I realize “dangle” isn’t accurate, he holds him in air) like that for a while holding the head only. Our kid weighs just under 40 pounds. This seems potentially really dangerous to me but can’t get him to take me seriously. He also dangles him upside down holding his ankle by one hand only, which again seems unnecessarily dangerous (at least as opposed to holding both ankles or holding one with both hands). He says I’m being ridiculous and so we agreed to ask a few doctor friends for confirmation but wanted to see what this community thinks. Is this normal physical play that everyone is doing?

Edit: thank you all for comments. Showed him first thing in the morning and he has promised to never do it again.