This is likely to be long so as not to drip-feed.
My PIL split up when DH was 10 and his Dsis was in her early teens. FIL had an affair and subsequently married the other woman. I get the impression that FIL put my MIL down throughout their marriage and never once supported her. She gave up working to have her DC but FIL said it she'd been useless anyway. That sort of thing. FIL saw his DC weekly and chucked money at them on birthdays etc. but offered no emotional support whatsoever. Both DH and SIL (his Dsis) were ridiculued in their choices and were forced to do what he said. DH dropped out of university twice as a result before going back a third time doing what he wanted. SIL gained a first, but FIL told her that she's amount to nothing and would be better off in a chip shop. 
Both got into debt (at a time when university and debt didn't necessarily go hand-in-hand) at university because he refused to offer any financial assitance: he has a good job and was earning an awful lot back then, as he was always telling them!
FIL's always disliked me - he actually told me I was a waste of time once and spread a rumour that I was forcing DH to covert to Judasim which, even if it had been true - which it was not - he should not have had any sort of issue with, given that he denounced his Catholic faith in his 20s. He had a face like thunder during our wedding (civil ceremony) and it is clear he has never approved of our marriage. In particular he makes derogatory comments about my job and my working.
DH and I met when we were 18. Been together 9 years and married for 6. We have 2 DC. Three weeks before DC1 was due, FIL decided that it was time for SIL to get on the property ladder so came up with the idea of buying our house from us so that we could buy his, and SIL would buy ours. We would sell complete with furniture. We'd only lived there a year ourselves and he had had nothing nice to say about it up until that point His house was nowhere near, but he thought it would be fine because I'm Jewish and "there are lots of Jews there". I'd be miles from my parents - my only family, and to whom both DH and I am very close. The catch was that he would own half our houses. And in ten years, we would sell up and split the proceeds. Suffice to say this did nothing to improve an already strained relationship.
SIL and her then DH decided they would buy FIL's house. When he refused to even contribute to the stamp duty (the house was over 250k) they backed out. He was being made redundant and was relying on us to supply him with funds from the sale of his house and he blamed DH and I for everything.
Over the next three years we barely saw him. We did try, but he only would come and visit when he was free (it didn't matter if we weren't) and would give us only two days' notice; sometimes just 12 hours. His lives around 150 miles away so clearly we don't expect to see a lot of him! We invited him to DD1's 2nd birthday but he refused. Imagine our surprise when he turned up at a garden party at MIL's the weekend before! He'd not RSVP'd yet, just said "Oh by the way, I'm not coming".
DD2 came along when DD1 was three. She was born the day of an uncle's birthday party, to which we had been invited, but having given birth less than 24 hours previously, were hardly likely to attend. The uncle in question was so kind about that, he understood completely and there was zero pressure to even feel bad about not going! FIL, on the other hand, was extremely cross. It meant that he might have to make an extra trip our way to see the baby. Indeed, he gave us baby clothes in neutral colours and a "congratulations on the baby" card. We didn't know what we were having, and it looked like he'd done that so he could just drop it off when next visiting without having to make any sort of special trip.
We've seen him a handful of times since then. A few weekends ago, we went away him, his DW, SIL and her DP. It was a horrendous weekend. FIL interferred at every step of the way, nothing we did was right. DD2 was coming down with something, and and she's 19 months, was a bit of a handful, as poorly toddlers can be! A few days ago, he e-mailed DH to tell him we need to sort DD2 out, that her ways need correcting and that we need to shout at her lots. Like he did across the table to make her cry. She's 19 mo ffs and we don't shout at our children. He e-mailed this, didn't even have the guts to have a conversation.
Writing it down seems minor, but I'm very upset and as usual, his behaviour is condoned by MIL and SIL as "just being FIL". I never want to see him again, and I never want my DDs to see him again either. I don't want them near that sort of negativity. Would I be right?
I'm sorry that this is so long. My heart is breaking for my DH who has put up with a lifetime of put-downs; how can a parent be like this?! I'm also upset that someone thinks we've made a mess of our 19mo.
Thanks for reading. I just needed to get it out.