Background:
Mil (exmil now) has always been attention seeking, childish and high maintenance but I do like her and in the past we have been close and good friends (as long as I've ignored the bad behaviour which has generally been on a Saturday night after to many vodkas) an example being when Dp and I told her I was pregnant with his first child (we were both late 20s and living together) she had a complete melt down and sobbed and begged us on her knees not to ruin her life, demanded no mention of it, repeatedly broke down over the next few months as she couldn't bare what we were doing to her, booking a holiday for the due date and taking all Dps immediate family with her so he had no support for the first week of his child's life. Ignoring her grandchild for 2 months and having counselling to get over our betrayal.
She is now incredibly close to her grandchild and is a doting fantastic grandparent, couldn't ask for more in regards to that.
There are many many more examples but I would be here all day writing them down. Her behaviour is ignored and forgotten by all and she has never apologised or mentioned it.
Again, I do for some reason like her a lot and she always seemed to like me too.
Fast forward to now:
I split with Dp in may and found out a couple of months later I was (am) pregnant. I must have gotten pregnant the very last time we slept together before not having sex for a few weeks (with him - I haven't slept with anyone else) it was a nasty break up, involving the police and courts but exp and I are now getting along well, he is a good dad and although isn't over the moon at having another child in this situation has accepted it.
Exmil however hasn't. When told a few weeks ago she said nothing at all, just walked away and didn't mention it again. I am currently 17 weeks and showing, his aunt and uncle made it very obvious that they had guessed so I told them that dc would be getting a new brother or sister in January. Exmil was there at the time and just walked away.
However after I'd left she had a full on rant at exp and other relatives saying that I was a slag, the dates didn't fit, I must be lying about whose child it is, demanding to know if exp had been shagging me after we split up (he has but he denied it for some reason) and now exp has been round demanding conformation of my due date and it's taken me getting a calendar out and showing him the dates to make him less suspicious although the seed of doubt has been sown.
The dates are out by a few days actually but she has no idea of when we were and wernt having sex, plus you need to take into account implantation etc.
Everyone now thinks I am a liar and a cheat and it's made me angry and upset. I reacted badly when exp told me and said he could tell her to go fu*k herself which went down like a lead balloon and now he is angry with me for my reaction.
How would you deal with this?