I couldn't imagine being treated, or treating someone, like that.
My GS's 2nd b-day party was on Saturday and I didn't realize until I saw there were two cakes that the party was also for my SIL, who's b-day was on Sunday. My daughter never said a thing other than about the 2 year old, they've only been married for 2 years and her DH was deployed for most of it so I didn't have it in my head yet of when his b-day is.
Anyway, I did not want to be one of those MIL who treat their SIL badly so I went out on Saturday morning before the party and got him a DVD movie that my daughter said he wanted. I asked her is there anything else he wants or needs?? She couldn't think of anything but finally said that he needed tank t-shirts. I got him 3 packages of 3 in different colors.