In Laws from H@#$?

When my husband and I were dating his parents and I got along and they had a wonderful relationship with my three kids and my kids loved going out to their farm, then this summer the husbands kids came to visit and decided my kids didn't belong there it wasn't their family. These two adults claimed to care so much about my kids and me and now they won't even acknowledge my kids presence when they come to my house and the kids are no longer allowed at theirs. I don't have a clue what to do and neither does my husband all we know is my kids are hurt and confused, the oldest is 14 and says fine their loss but the other two are only 6 and 8 and don't understand why someone claims to care one day and doesn't the next and what is worse these are "good christian people" that make sure they are in church every sunday. what a crock. Anyone been through this and how did you cope?