My Suspicion On My Husband

My husband and I are married for barely 1 year, have an 8 month baby.

Our baby doesn't live with us here in the city, since both of us are working, our baby lives in the province with my mom.

In the city, we are renting an apartment together with his 2 co-workers (girls). I could say that my husband is a good husband.

However, I'm quite jealous with one of his co-workers who lives with us in our apartment. This girl loves to wear shorts and body fit.

I am not sure of my suspicion, but sometimes I would notice that my man would stare at her.

I confronted him regarding this, since I've been very difficult of him these past few days with no reason at all...not him knowing that I'm just jealous.

My question are...

- How could I know that he has a crush on his co-worker?
-What should I do?

Thank You very much for considering my problem.

Mrs. Suspicious