Hi Doctor. My Partner (male) Has Just Notice A Hard

Hi doctor.

My partner (male) has just notice a hard lump (bigger than pea sized) under his skin on the left side of his face just below hairline in front of his ear and around his jaw/cheek bone. Hurts when pressure put onto it.
Also been past few days had problem with his jaw pain and cracking.
Not sure if it's anything to do with it.

Thanks