A side hoe and your husband (Thoughts 🤔)

Ok from the top. My husband and I work at the same warehouse different departments. I'm currently out on maternity leave though. Before I left we had lunch around the same time and the front office girls would be getting to the break room when I was wrapping up. NEVER NOT ONCE heard/saw my husband speak to Mary. A little background on Mary. She tells people she's gay and has a gf but she's been sneak freaking with another guy who has a fiancé and kids for a few month's. This past week she added him on Snapchat Instagram and I think Facebook. Then Friday the guy she's been messing with approached my husband about if him and her had something going on (which is dumb as hell because she's his side hoe. He has s fiance) My husband and Mary both leave the bar they were at because he was very drunk and wouldn't let up. My husband is about to head home but Mary ask him to come to a second bar to talk about what happened and explains herself to him and tells my husband the guy is a stalker and possessive and he was just a fling and she regretted it. Now my husband doesn't think that I should be as ready as I am to approach Mary. But as far as I'm concerned she's a side hoe and a dickNdike so I have a issue because it now looks likes she's trying to direct her attention his direction but he stands firm she is not.

What would you think/do?