Was talking to my fwb and asked why they were in a bad mood yesterday. She responded by saying her ex posted this thing on social media about her and also said she hasn’t talked to him in months. Now I know that’s a lie as I’ve straight out seen her messaging him in front of me.

How should I deal with this? Confront? Demote?

I’m fine with them talking to other guys seeing as we’re not exclusive but feel very disrespected from the lie.