Well Tom, my W was a dear on Father's day. She got our DD3 and her stepkids (my kids from M#1) to cooperate and make me breakfast, went on a bikeride with all of us, and even took the initiative to pick up the check at dinner, (more of an "appearance" thingy, as all the money to pay the bills comes out of the same pot, but, hey, I appreciated it.)
THe only thing my W didn't do was boink me. And since I didn't really expect that she would, I wasn't truly disappointed.
As for your kids, at least they called and wished you well. But I have to agree with annette that it's really their responsibility to wish you HFD and to celebrate it with you, since you're their Dad, but you're not your W's dad. Still, three freakin' words would have been nice. Why not tell her that, in, perhaps, less of an emotional tone? And if she gives a WTF? look to you instead of an apology, then save some money next year and buy yourself something fun on Mother's Day, instead of wasting your money on her.
Hairdog - who, believe it or not, made the conscious choice not to ruin the almost-perfect Father's Day by asking his W to ML, knowing that she'd probably say no.