slip out of
US /slɪp aʊt əv/
UK /slɪp aʊt əv/

1.
to escape or leave a place or situation secretly or unnoticed
:
•
He managed to slip out of the meeting without anyone noticing.
•
The cat tried to slip out of the open door.
2.
to be said or revealed unintentionally
:
•
The secret almost slipped out of his mouth.
•
A small groan slipped out of her as she stood up.