I have a feeling that I know what the answer will be but here goes.
When we separated, all XH was bothered about was keeping our 5 bed marital home. I couldn't be bothered fighting him over it so I moved into a small 3 bed rental with our DC. Since then, he has moved two lodgers in (but has not increased his maintenance to reflect this even though the house is almost mortgage free). One of his lodgers has a young child who stays at the house on his contact weekends.
Following XH's last contact, our two DDs came down with a stomach bug. After speaking to XH, it transpired that the lodgers child had also stayed that weekend and had been ill with the stomach bug.
I'm really angry that he knowingly exposed our dc to this illness. They had to have 3 days off school. XH has never ever taken time off with them when they are ill. I am self employed so do not get sick pay or leave for dependants so I am now very behind with work having stayed at home with them when they were off. He took them abroad this term during school time so now the school have written to me warning that their attendance is unacceptably low.
And to top it off, I am now ill with this bug. I have a chronic illness that means I am more susceptible to bugs and am already at the tail end of a 6 week long very nasty cold. I am also meant to be working this weekend. It's an extremely important event which I will have to attend - poorly or not.
XH maintains that they would have got it eventually anyway but no sickness bugs are going round at school or in my circle of friends/family. I could understand if they were inadvertently exposed but he knew full well that they would come down with it and I suspect that if it was he who would be inconvenienced by their illness, he would not have allowed them to be exposed like this.
So AIBU to expect him to have taken steps to minimise the chance that they would be infected? He was rather abusive to me when I said this to him but then he's a nasty abusive man anyway so needs no additional reason.