Is it ok for an husband to invited a field worker to a family affair?

My husband is working in another state. Our children lived their as well. I was going to fly to the state so we could all be together for his birthday. He decided to invite this field worker to stay with us at our children's home. He said that he did not want him to be alone.. (The man is 45 years old). This was a family planned weekend. Anyway, I am still angry.