So, I have two dc's one is brand new. 
My own mother is sadly no longer with us.
We are fairly close to bonkers in laws. Normally.
Only, just lately I feel let down by them. Things to do with birth of dc2, and in the main, FIL being a first class twonk of the highest order. He is a crap dad really, not interested in DH, drinks a lot and makes a prat of himself at most family gatherings. Last week I was laughing with mil about the fact that I was an ugly baby and he said "you still are" and kept on saying it 
too many times. He is just a prat generally and has no real mates. Dunno what mil sees in him but she is a bit strange sometimes also.
Anyway, last week FIL went too far and mil kicked him out. Cue him storming round to various members of the family trying to get the story straight that HE left HeR actually, and dragging everyone into it when we didn't care they are always at it sort of thing.
Of course, now they are back together, happily slagging everyone else off and nobody has received an apology for their behaviour. As usual. So, in the midst of all this is fil's mum, DH grandma. She told me last week that FIL turned up at her house really being nasty and upset her a lot. She is his mum and he blames her for everything. But she is an old lady and I felt sorry for her.
My big mouth ended up inviting the in laws and grandma in law over for mothers day lunch. Now, I am starting to regret it. It's not the cooking and clearing when I need a break too but the fact that FIL will sit on his ass with his coat on doing jack shit, mil will get pissed, grandma in law will probably sit brooding on his behaviour last week and poor DH will probably get stuck with the kids and fetching and carrying for the lot of them. Plus there will be the elephant in the room that is last weeks kick off hanging around and nobody will want to mention it for fear of upsetting poor old dickhead FIL.
My invite was well meant at the time and intended to clear the air, but fuck me I'm regretting it now. AIBU and should I just get on with it?