Hi Kasandra and welcome!

You've come to the right place. We "get it" here and we support each other on this confusing journey.
What's helped me get through? This board, first and foremost. So much wisdom, support and advice to be found here. Also, therapy. I have an excellent therapist who has some experience with BPD so she's a great outlet and source of more information. Do you have a therapist?
Have you read our article about
boundaries? Here are a couple of things I've learned:
1) Setting a boundary doesn't mean you have to tell the other person you're setting it or even what it is. It can stay inside your own mind. When you act on it, you don't have to tell your H "This is a boundary." But, you do need to be consistent about enforcing and holding the line.
2) When you do enforce a boundary, even if you haven't had the "this is a boundary" discussion, you may very well get a very bad reaction.
I don't know if you have children or have spent much time around them, but think about a toddler used to getting his way. Usually, if he throws a fit, his parents will give in and he gets whatever he wants. Parents decide to make some changes. When the child wants a cookie before dinner, Mom says no. Child throws a fit. Mom doesn't give in. What's going to happen? The child's probably going to increase the intensity of the tantrum. Now, if Mom gives in at some point, she's taught Child that tantrums still work. If Mom holds firm, eventually Child figures out that this method no longer works and the tantrums will cease.
It's called an extinction burst. The same thing can happen with adults. If a behavior has worked for them in the past, they'll keep using it. If it stops working, they'll ramp up the intensity (most likely) but will move on if you hold firm.
So, to answer your question, you may not be able to avoid a big negative reaction. A lot of that depends on your relationship history, your H's level of self-awareness, timing, etc. But, if you hold firm to your boundaries, the negative reactions should decrease and disappear.
[Now, all this is assuming there's no history of violence because that can be a trickier situation. Has there been physical abuse?]
There are communication techniques that may be able to make things a bit smoother with boundaries and even just everyday communication.
If you haven't already, check out these articles and workshops:
SETDEARMANValidationI've thrown a lot at you so take your time. I hope when you feel up to it, you'll take a look and let us know what you think -- also more about your relationship.
Again, welcome to the family!
