I didn't blow my top on BM but I did let her know about herself. She was always 'very nice' to me after she met me in person, for about 2 months. She got an attitude with me & I just asked her, sternly "Who do you think you're talking to?" she backed off.
Now I won't allow her to talk to me. She hasn't said anything about it, but she got an attitude with DH the other day & he told her "See that stupid shit is exactly why nobody will talk to you" lol! MIL & I & FIL & basically DH's whole side of the family avoids her.

Ok, yes. But I wouldn't give her the satisfaction of knowing she had gotten me.

I think it all depends on the situation. There is a blogger on here who posted about BM coming into her home when no one was home to drop of the skids stuff.... IMO this is a perfectly acceptable time for a SM to blow her top because it directly affects SM, her privacy and her home... There was another post recently about a SM who was upset about the way her skids were dressed... well, IMO that is not your place to blow your top at BM, it's something you take up with DH, refuse to go with the SD places as some of the commenters suggested, or disengage from completely... if it doesn't directly affect you or the safety of your family including skids then it's probably inappropriate to "blow your top"

Yes I did blow my top finally and I am ashamed. I got a lot more satisfaction at siccing our lawyer on her when she would take DH to court for the annual mo' money grab.

I "blow my top" as you do, notasm. I don't curse or scream or otherwise act like an idiot, but I will not hesitate to calmly and politely tell you what I think. I also agree that it is pretty effective. I am typically a fairly pleasant, mildmannered sort of individual and sometimes people mistakenly get the idea that I will endlessly take their shit and never say anything about it.

BM is one of the people that I've had to let know that I will not take her crap. Her, my fil, my sil-all people that ive had to let know in no uncertain terms that I will not take any of their bull shit. Amazingly they all have left me alone from that point on.

I never loose my cool with BM it's awesome because it makes her look crazy while I'm cool as a cucumber looking askance to those around us to take pity on the poor creature who can't seem to control herself in public even. I use my intelligence, and even voice to make her look like the stupid crazy cow she is. Best part is usually when the kids principal has to step in (I think this man follows BM and is studying her lol he has a masters in Psychology) She's done the bat shit thing at open house, Christmas performance, once at the store and once in a restaurant the principal just happened to be in the restaurant that time.
Luckily the kids only saw the open house rant. I smiled and told her "I'm so very sorry you feel the way you do, maybe we should address this in a less public matter?" which usually makes her start the "what you a chicken shit, you know I can beat your ass you stupid, c, I'll *insert threat here*" I return to the "you realize your making a spectacle of yourself right now, and I'm sure you might have some possible valid concerns, or are maybe just confused on your role here, but it would be wise for you to cease before matters her begin to involve the police, and my attorney." cue principal, store manager, teacher, my SO. (SO intervening just equals screaming of an incoherent nature from her.) I mostly avoid her because it's not good for the kids, and the principal has told her this year that one toe out of line she will be banned from school events (it's not just me she apparently is always screaming threats at the kids at pick up and drop offs and latchkey when they kick her son out for his behavior)I let SO handle any attempts to defend me against her stupidity because I really don't care what she thinks of me the opinion of a moron is not my concern.

Yup, i call them out on their BS and if they don't like it OH WELL. They can try to be disrespectful to me but I WON'T ALLOW IT. I take the time to take care of kids that are not mine, i don't talk bad about their mom (not in front of them) I help as much as I can. I deserve a little credit so they know not to come at me sideways cuz i will NOT bite my tongue.

I've done it, more than once. And I will do it again if it is necessary. I refuse to let anyone tell bold faced lies about me and convince a child that I love that I am a bad person, when I have done nothing but love, care and provide for him his entire life.