Couldn't lie straight in bed Australia New Zealand informal
To be dishonest or deceptive; to lie a lot
Don't care about what John has said. That guy couldn't lie straight in bed.
No one believes what she is saying to be true as she couldn't lie straight in bed.
White lie
Seem to be very suspicious or morally unacceptable
Used to imply that someone is acting as if he or she is demure, innocent, sincere or reserved but they may be not
Very dishonest and deceptive
A humorous way of saying that what one has said is just what they acknowledge and may not be entirely accurate
Mike: Have you returned from your vacation on the beach? Your skin seems to get tanned.
Jenny: My skin is always dark. That's my story and I'm sticking to it!