drop (one) in it
To embarrass one, often by revealing unflattering information. Primarily heard in UK. When Paul told the boss about my role in the printing mishap, he really dropped me in it.
drop someone in it
BRITISH, INFORMALCOMMON If someone drops you in it, they cause trouble for you, especially by telling someone about something wrong that you have done or something that is embarrassing for you. He was dropped right in it by his own officials who admitted that they do not know what he is talking about. By the time the police caught up with him, his mates had already dropped him in it.
drop someone in it
place someone in an embarrassing or awkward situation. informal