grinding

Hey all! New member here. I've always been curious about this so I wanted to chime in. My boy Vanta when I pet him usually starts out with very pronounced "I like this" tooth grinds, usually in patterns of three grinds at a time. Sometimes, if I'm petting him for longer, he starts doing quieter...

This is a very new sound for him to make. He started it three days ago. At first I thought it was tooth grinding from pain, I got him to the vet ASAP and she found nothing wrong with him. He’s eating, drinking and pooping normally. He seems to make the sound the most when he is grooming, but...