I think that you and your husband should agree about where you draw the line around your marriage--with lots of discussion--and then apply that to EVERYBODY. That's the general way to handle it. The specific way would be to address each issue on a case-by-case basis and let that build a pattern that everybody will pick up on and get used to.
Keep in mind that, because you come from different places, different backgrounds, people will tend to just do what they're used to doing unless you give them reason think otherwise. The longer you let it go and think about it, but the bigger it will be when it does finally come up, and you don't necessarily want a blowout, right? You just want your boundaries to be respected and, probably, understood.
I don't know your marital history. If you haven't been married long or if this has never come up, then maybe you can casually mention it in conversation, maybe a group conversation. You don't have to address anyone in particular, but you can offer up your feelings about something and then explain how you have come to feel this way. This will get the ball rolling, and it can remain open for discussion. Once you feel understood, you might even ease up a bit. Maybe you and your husband never established your rhythm and it feels like you are following somebody else's rhythm.
(I feel like I'm rambling, but I hope that I have said something that is helpful. You don't sound like you are asking for too much, generally speaking. I just can't tell much without more detail about how you and your husband interact with each other and respond to these so-called intrusions and what it is that is getting under your skin. I just know that talking with a mate about the differences between you and his/her family of origin can be a little tricky.)