We were very recently married and have only 3 visit records of us crossing the border to see each other, all in the last 6 months. I thought the relationship might be new enough for that to be ok to say, as it is the genuine truth. We don't want to be apart and want to visit and ge to know each other better until I can go down to the US. I don't know if I even need to worry since we are genuinely not trying to trick the system and stay or anything, just worried we'd have to be separated while my US spousal visa papers go through, which would be too long for comfort.
As long as he can show proof that he has job/residence in the US, he's okay. POE officers are a little wary of Americans coming over purportedly for a visit and staying longer than 6 months because they wanted to apply under spousal/common law partners. And as Baloo has said, the fact that he is sponsoring you for a spousal visa to the US shows it is not his intention to overstay in Canada.