Received annalingus/rimming. now have itchy bum. sti? have hpv in cervix and bf has done unprotected oral on me. so he has it- transferred to bum?!

Not HPV: HPV infections don't itch -- typically there are no symptoms at all, except skin bumps (warts) in some HPV infections. Yeast is the main causes of genital and/or anal itching. STDs are possible from analingus but unlikely. Keep the area clean and dry, or maybe try an OTC anti-fungal cream (or vaginal cream if you also have vaginal area itching or irritation). See a doctor if these don't help.