A parent who can't accept the relationship their child is in, because they are protective of their child and/or do not like their child's significant other. Will lecture their child on the cons of their relationship and go to lengths to end the relationship. The parents may appear to even like the significant other when talking to them, but call them names behind their back to brainwash their precious offspring.
His mom called me a cradle robber
. Can you believe that? I'm not even that much older than him. She's the altar robber.