Dear Nazar:

If she is your girlfriend, has agreed to a committed, monogamous love relationship with you, then she  shouldn’t be friends with an ex boyfriend unless she has a child or children with him who need  to be  co-parented, or the two of them have  property together that  needs  to be managed or sold, or the two of them are work associates who see each other daily or occasionally as work colleagues. If there is  nothing that connects them in these or similar ways, a friendship with him is not congruent with a  relationship with you, I believe.

He is trying to resume a love relationship with her and she is not interested. This by itself makes a friendship impossible, one person interested in more, and the other not interested.

She didn’t tell him she has a boyfriend. A friend tells a friend that she  has a   boyfriend.

If I was you, I would question her about the nature of the friendship she thinks she has with him or hopes to have with him, why she needs or wants such/ what  is her motivation. If you ask her and want to share her answer here, please do and I will give you more of my input.

anita