Alec's dad is pretty absentee, only showing up a few times during the show, and tends to favor his other two kids. He's vaguely approving of Alec, but they don't interact much, unlike Alec and his mom, who he gets to know better throughout the show.
Peter never knew his dad, and just had his uncle ben, who he lost too. He tends to look for dad-like qualities in older men he knows, without realizing it.