Ex Still Calls Hubby's Parents Mom and Dad

The ex is calling my husband's parents "mom" and "dad".  She did on their facebook today.

So what's the big deal about that?  Lots of ex's still call the parents of the father of their children "mom" and "dad", right? 

• First, they were never married and they didn't have a good relationship during their relationship and they didn't have one after it ended.
• Second, he never loved her - they picked each other up in a bar and she got pregnant, tried to make it work for the baby, blah, blah, blah. 
• Third, she hasn't bothered to send "mom" or "dad" any pictures of the kids at all this year and when they come into town, the stepkids are always too busy to spend any time with them (like they are with us) according to my husband's parents. 
• Fourth, it's been over for almost 16 years and she couldn't drag him down the aisle during their relationship.  Time to move on, go on the first date since my husband left her 16 years ago, get a life, etc. 

Yeah, it bothered me a bit.  I know a lot of ex's still call the ex-in-laws "mom" and "dad" still but they were never HER in-laws and she has been nothing but nasty to my husband for 16 years.  They are grandparents to her children but they never became mom and dad by marriage. 

Does it bother you if the ex calls your in-laws "mom" and "dad" still?