Without a by your leave; without so much as a by your leave
Definition 1 of 2
Pro Tip 1/3
Permission Ignored
Used when someone acts without seeking approval first, often leading to surprise or annoyance. He joined the trip without a by your leave, which baffled everyone.
Pro Tip 2/3
Informality
This phrase is informal and best used in casual conversations, not formal settings. She entered without a by your leave, as if the house were her own.
Pro Tip 3/3
Disregard
Implies carelessness towards others' opinions or rights in the acted-upon situation. They started the project without a by your leave from the committee.