I just want him to be happy

When I was younger I fell in love with one of my best friends. We dated for over a year, I was happy, but I don't think he was that happy. He's a Sagittarius and I am a Pisces, we quit dating and still remained close friends. I've known he's liked this friend of mine, who I adore, and they're astrological match is wonderful, she's a Libra. We've been friends for five years and I tease him about her and hint that he should muster the courage and ask her out on a date. She's sweet, cheerful, beautiful, and amazing. They're one of my otps, usually most ex-girlfriends don't want their ex-boyfriends dating their friends, but I trust the two of them completely and I want him to be happy. Is there anyway I could convince him to get the courage?