1. I designed Pipp and Zipp's father/the pegasus king since I have never actually seen any yet
and 2. I had a theory about why he's not in the family anymore
(Based off the lyrics of Pony Love)
I think the king might have been a jerk
Who wouldn't let queen Haven make any of the choices
"My time to speak, Came and went like night"-her not being able to get a word in and being overshadowed by the king
"The mountains I have climbed, The truth is if it happened once, It happened a hundred times"-Her problems with him just kept coming up, and happening again and again
"All I ever wanted! To be closer to feeling pony love!"- He may not have loved her as much as she loved him, if at all
Maybe by the time the princesses were born, she became fed up with his selfishness she left him and became ruler of Zephyr Heights on her own
Perhaps he only married her for the royalty
not provided yet