Seriously? All you single moms need to understand that you are NOT a dad. You are a WOMAN. Celebrate your motherhood/parenthood on MOTHER'S day. I find it offensive that some single moms think of themselves as a father to their children.
I get that sometimes kids WANT to give you something and that's fine but, to expect or go around wishing all the single moms a happy father's day is plain rude and stupid.