As per Starcasm.net, David and Hilary are not and have never been in a relationship.
David Visentin is married to a woman named Tia and they have one son, Logan. Hilary Farr on the other hand, revealed that she endured a “horrible, horrible divorce” right before auditioning for Love It or List Is. She has an adult son.
Hilary and David actually met for the first time after they were cast for the show in 2007. Hilary told Post City in 2012 they quickly developed a “genuine deep affection” for each other.