"Complain about us taking too many weekends off. I dare you."

I work in a medical center lab, and it runs every day, all day. We don't stop at night, weekends, or holidays, but only 2 people need to work those times because it IS much slower. I have a co-worker who chose to work the weekends and have her days off mid-week, and I work Tuesday-Saturday. This normally leaves one day a week for our boss to either find volunteers or use the rotation schedule as is stated in the contract.

Our boss has made comments to my coworker who does the full weekends a