DH has never had a good relationship with his parents. They have always been of the attitude that he "owes" them for everything they "sacrificed" to bring him up. Whenever we gave a present it was too cheap, if we went for lunch we left too early, he didn't phone often enough, we didn't ask them to babysit enough, but if we did, we only wanted them when we needed them etc. MIL even phoned the day after DS1 was born to complain that the Mothers Day card we'd sent her was too small.
For a while MIL had DS1 one day per week while I was at work and that arrangement was OK, but the day before I was due to go back after DS2 was born, DH upset his mum over some small slight and she decided she wasn't going to do the childminding anymore. Obviously her choice, but it gave us less than 24 hours to make other arrangements. I think she probably thought we'd be so desperate we'd have to beg her to come back, but as it happened a friend who had been a nanny before her own DC was looking for part-time work and she had them for me - we'd only asked MIL to keep the peace, as my parents were having the DC one day pw too and everything had to be "fair"
DH decided he'd had enough, using the children against him was the final straw and we haven't seen them since (8 years). I'm sad my DC don't know their GPs and I suspects DH will have regrets later, but he insists life is better without them (it's certainly less stressful)
Anyway PILs always send cards and cash for DCs birthdays, Christmas, Easter etc and since they've been old enough to write DCs have always written to thank them. The only other contact has been cards I've sent for their birthday and Christmas enclosing photos of DC. At Easter DCs wrote lovely letters which GPs have replied to with a small gift to say thanks.
So, I'm now thinking that I encouraged them to write nice letters, but where does it end? DH is not at all happy about a regular correspondence with the DC and as the DC get older who knows what their private mail could include.
I've tried to keep some small communication open (with DH's knowledge, but not exactly approval - he's basically said do it if you want, but refused to get involved himself) but now it seems I might have stirred up trouble for the future.
Sorry it['s so long, if you've got this far WWYD?