sneak in

Short definition from Wiktionary

Verb

1. 1
   To enter without being noticed.
2. 2
   To barely advance or be allowed entry in a competition or organization despite minimal credentials or competitors thought to be superior.
3. 3
   To take (something) in covertly; to smuggle.
4. 4
   To insert (words, ideas, etc.) into something without drawing attention to it.