AITAH for telling her husband she met my fiancé?

AITAH for telling her husband she met my fiancé.

I recently discovered my fiancé of over a year had met up with another woman. This woman came to light towards the start of our relationship, I saw she had text him asking him for a nandos date. I left it at the time because I knew he had a lady friend and have no issues with it... until the other day. I came across some viagra and noticed some missing, I randomly asked him about this woman and if they talk or meet. He says yes I met her after Christmas.. In my head I'm like when? he never once has spoken to me about her or said they meet. We lived together at that time and so it confused me why that was a secret, he tells me theyre school friends and he gets relationship advice from her about us. I stew on it for a few days and need answers.. I message her husband to see if he knows about their really good friendship, because if he does then there's no secret or issue for me. And surprise, he doesn't know, he tells me he suspected they spoke but she denied it, said they didn't go school together, they are exes. Now Im wondering wtf. Since then I've had my fiancé end it and abuse me over it.. her family members messaging me on social media threatening me and giving me abuse because I apparently broke them up and ruined their childs life. I just feel they shouldn't have kept it secret from their partners.. Not sure if anyone would have done the same in my position, but felt the husband had nothing to gain by lying, and if I asked the lady friend she wouldn't have told the truth..
AITAH for telling her husband she met my fiancé?
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