A "rim job" is a slang term for analingus. That means oral stimulation of the anus. A lot of people of all sexual orientations and genders enjoy analingus. People practicing rimming should be aware that it is risky in terms of disease transmission unless safer sex practices are used.
He shows impressive early awareness of technique and shoots a good load considering he is standing! The teen guy jerks his big cock like a real professional… as horny as he cums in his own face…. Contacts, those eyes are wild.