Co-workers

My husband I met as co workers years ago. I quit my career to be a stay at home mom to our 3 children: just before birthing my last baby, my husband was having an emotional affair with a much younger co worker. We have relocated since then, I have this feeling there is something going on with a new co worker but there is nothing to back up this feeling. Except; she came to our home for a dinner this week and I noticed a certain look between the two.

Please tell me I’m being insecure and paranoid.

Should I speak to him about it or just not say anything and let it go?