Is this friendship sus?

My husband has a female friend overseas that he talks to on a regular basis? They went to college together and has kept in contact and he caught up with her overseas a few years ago. I told him to promise to never talk to her again and he promised. But today I saw messages to his sister saying to contact her as she can be a good reference overseas and also a job reference for his brother. I understand they are college friends.. I am with him and she is overseas, he is entitled to friends but no need to lie about the friendship

Is this friendship sus?
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