I 26f found out my boyfriend 28m is married. Should I tell her and ruin her new family?

met my boyfriend about 7-8 months ago and we made things "exclusive" about 2 months in. I noticed he was acting strange about two months ago but he works in law enforcement (in my town) so I thought maybe something happened that was bothering him.. turns out, that was when his wife delivered their first baby.. I found out due to an innocent that happened with another officer and because he was acting strange, googled his name and found an obituary with his name and his wife's name on it, found her Facebook and saw their newborn baby. I didn't tell him that I knew he was married and just ended the relationship saying I was unhappy. My question is, should I tell her and destroy the family she just started or keep this to myself and just let him go (I do not want him at all after finding out this information). What would you do in my shoes?