What would you do if .....

[auntyquated]

your DB & SIL treated your parents like sh1t??

keep out or say something to him?

Message withdrawn

This happened in my family and we occasionally made comments to them but it only stopped when my mother put her foot down and told him that she was ashamed of him as a son and that she hadn't brought him up to be so disrespectful.
The thing is is that they are all adults and have to be responsible for their own actions so saying something to your db probably will only cause strife.

Depends on how/what/why.
If dm was getting really hurt in the process I would step in.

i knew that this should be the approach but keeping my mouth shut is hard!

it is upsetting them but how much i don't really know.

It has to be up to your parents tp sort it I'm afraid. If they do something particuarly horrible it would be perfectly OK to say something on the spur of the moment - but not to drag the whole situation up and have a big row. That wouldn't help anyone - family feuds rarely do. My DB does say some nasty things about my parents sometimes - he has issues with them from childhood that I'm not really clear about - and some of them are true but as I'm very fond of them I can gloss over them. He has upset mum in the past but if she can get over it, I just have to. Do you know why they are so nasty?