It's safe to say that David doesn't get along with his father. Not that we can blame anyone born to Michael Mancini for that.
Added:
When Jane returns to Melrose Place, she does so with an agenda. And it has a lot to do with Ella.
Added:
Jane Mancini is back! Following the death of her sister, she visits her former apartment building.
Added:

Melrose Place Season 1 Episode 4 Quotes

My name is Jane Andrews. I'm Sydney's sister. I'll be your new landlord.

Jane

I have nothing to hide. I didn't murder Sydney.

Ella