slip out - Wiktionary, the free dictionary

From Wiktionary, the free dictionary

slip out (third-person singular simple present slips out, present participle slipping out, simple past and past participle slipped out) (intransitive)

1. To leave quietly and unnoticed.

   Synonym: take French leave

2. To go out for a brief moment; to pop out.
3. To be said or revealed by accident.

   I was talking to Jim, about Paul and Ethel, when it just slipped out about their possible divorce. I’m sorry.

4. Of an object: to work loose and slide out of proper position.

• slipout (noun)

• outslip