have your head up your arse
have (one's) head (stuck) up (one's) arse
rude slang To be totally self-centered. Primarily heard in UK, Australia. Of course Josh had no interest in my ideas—he has his head stuck up his arse, as usual.
have your head up your arseBRITISH, INFORMAL, VERY RUDE or
have your head up your assAMERICAN, INFORMAL, VERY RUDE
If someone has their head up their arse, they say silly things or behave in a silly way. `That's what Peter said.' — `Well, Peter has his head up his arse.'