I think your Boston is unhappy and confused with the addition of the husband to the family, let's face we all feel like that sometimes! She is scent marking in order to tell your husband she is the boss of him. It happens only sporadically because she is either happy to let him be in charge and then he does something that makes her wonder if he really knows what he is doing, or, more likely, she feels that she is charge of him (very stressful) and sometimes he does something that makes her feel that perhaps he is challenging her for control. Poor hubby is in an impossible situation - the very fact that your dog is scent marking in the house strongly indicates that the dog thinks she is also the boss of you, if you were the boss it wouldn't enter the dog's head to behave this way. Hubby has had to treat the dog the way you tell him to or else you will be cross and upset with him but something is giving the dog mixed messages. Things to think about - do you leave food for the dog to pick at when it wants? Do you let the dog onto the sofa for a cuddle, or as soon as you sit down is the dog in your lap? Do you let the dog into bed with you? Is the dog neutered? How does she get on with other dogs? How much time do you spend with constructive play (training)? Is your dog okay off lead and can you recall whenever you want to? Is she protective over toys or food? Do you have other pets? Just a few things to think about, this shouldn't be a big issue to resolve, we just need to get to the root cause. Kudos to Hubby for putting up with it though, does it cause problems/arguments?