I know he’s cheating on her

Long story short, my husbands coworker is cheating on his wife with several bitches in their own bed. I know this bc hubby told me he told him. I met his wife a few times and we really hit it off, she’s super cool and we really got along well. My hubby and the coworker had a falling out recently and we were never really close, but I want his wife to know. I want to anonymously tell her to install hidden cameras or something in their bedroom so she can catch him. What should I do?!?! If I were her I would want someone to tell me. Advice please, or should I MYOB?