Our new 3 year old dog becomes very upset when my husband and I are intimate. He never growls and rarely barks. He loves my husband and was cuddling with him shortly before. When we started kissing and such, he became angry and started growling and barking furiously at my husband. Semmed as if he were protecting me. Is it possible he saw something in his past and/or is this normal?

Your dog has learned a bad behaviour and unless you put a stop to it, it will only get worse.

I'm attaching a video clip, this may help. I'm not saying that your dog is anywhere near as bad as the one on this clip, but, unless you put a stop to this behavior, it could escalate to this point.

YouTube - Cesar Millan and small dog Demon Chihuahua, dogs training