Is this protective behavior?

Our 3 year old male cat Sully likes listening to videos of vas meowing. However, we haven't played on in a few weeks since we got 17wk old Boo, a female. I played them and he looked for the noise and kept walking by her and at one point stood with her under his front legs and licked/nipped her neck til she looked up at him and he proceeded to clean her face. He then kept trying to bathe her.

I hadn't seen him do this. I've only seen him check on her when cried when we had to give her medicine.

So it this just him protecting her or being motherly? We were told he may develop maternal instincts being around her.

Cats who like each other will groom each other.  Eventually she will groom him as well.