DH and i are friends with a couple, and have been for a long time. Now we've fallen out.
Both have children from former rships- he pays child maintenance to his XW for their child, she receives C.M from her XP for her DC she had with him.
On separate occasions in the past, including this year, she has openly called out her XP to friends and publicly via Facebook for being late or absent with his CM payments, saying how out of order he is to not put his children over his girlfriend and his social life, they came before she did, and his unreliability only lets them all down (i totally agree with that btw).
Anyway, we've had a bloody fallout because I couldn't keep my bloody mouth shut, and would like to know if people think I actually do need to back down or not.
They came to see us Sunday for a drink at ours, and she brought up her DH's X.
"She's not happy with us at all. Because of Christmas and everything going on, we've had to text her and say we can't pay DS's money until January".
In my defence, at first I did try to be nice, and say how hard that would hit anyone a week before Christmas- can't they at least find half of it and then the other next week? She just said "Well no, and quite a bit of the money actually went on presents for DS, so technically he'll getting the money this month anyway" 
I had to ask because I'm a twat probably "So why is your Ex an unreliable bastard if he misses a month to you and your two, but John* does it to his Ex and son then that's fine? It doesn't make sense"
She didn't answer, the conversation went a bit awkward, then her DH made excuses about work in morning and they left.
My DH has received a msg yesterday night, from him saying I was "absolutely out of order" and "She's really upset DW, we thought she'd have apologised for that by now".
I haven't replied yet- I still don't think it was bad to call them out on double standards, or was I?
Friends should be able to tell each other if they think you've taken total leave of your senses shouldn't they?
Or am I just too stubborn?
I'm prepared to be told if I'm wrong, or should have just shut up 