Confused Maltese? How to help it?

We adopted 3yrs old maltese, she was used for breeding. She is great with me & she okay for most part with hubby, except when he comes home she turns into Cujo. After a few mins, she is fine. She sleeps with us, he works nights, so when he comes to get into bed, she starts snapping & growling, I put her on the floor and once he is in bed, she is fine, she licks him and snuggles next to him, buy why does she attack when he first comes in and how do I stop it.