不關痛癢

unimportant / of no consequence

no; not so / (bound form) not; un-

mountain pass / to close; to shut; to turn off / to confine; to lock (sb) up; to shut (sb in a room, a bird in a cage etc) / to concern; to involve

ache / pain / sorrow / deeply / thoroughly

pain and itch / sufferings / importance / consequence

to itch / to tickle