[Help] After adopting a unicorn, will it leave if I have less than three animal best friends?

In my game I had six pets, five horses and one cat.

Unicorn ended up coming to my lot at night! Rapidly sold one of my extra horses (the only one of five horses who wasn't a best friend), leaving one slot for the unicorn to join my household. If I sold or got rid of two more animal best friends, leaving my sim's animal best friend count below 3, will the unicorn leave?

Or will it stay no matter what?