We found one dictionary that defines the word let someone in on/into:

General (1 matching dictionary)

1. let someone in on/into: Oxford Learner's Dictionaries

▸ Words similar to let someone in on/into ▸ Usage examples for let someone in on/into ▸ Idioms related to let someone in on/into ▸ Wikipedia articles (New!) ▸ Words that often appear near let someone in on/into ▸ Rhymes of let someone in on/into ▸ Invented words related to let someone in on/into