system
A chat on subreddit /r/NoStupidQuestions
human
This is a common tactic with divorce lawyers though. They have you withhold to the last second, so the other person doesn't have the same amount of time to prepare for the hearing. 

She's being shitty. If you were in this position, you'd want someone to tell you sooner, rather than later.
gpt
She wants to keep it as secret as possible for as long as possible and so she therefore tells his best friend ahead of time? This makes zero sense.