consider this: Obi Wan’s been in love with Anakin for years, hopelessly pining. he’s fought side by side with him throughout the clone wars, they’ve saved each other countless times, and, in his eyes, they have an unshakeable bond. they’re each other’s closest friends. he sees Anakin struggling, and sees his anger and sadness, but when he reaches out he gets pushed away. Anakin goes to the chancellor instead of Obi Wan, and it hurts, but he understands: Obi Wan is a jedi, after all, and Anakin is angry with the council. Anakin slips farther and farther from him, and obi wan can’t be there for him, even though he wants to be, too wrapped up in the war.
then, his troops turn against him, try to kill him. he survives, and his first thought is Anakin: if the clones are turning against the jedi, then he must be in danger. Anakin’s alive thank god, but Obi Wan then has to watch as the man he loves casts aside the jedi order (and therefore him) and falls to the dark side. then, he watches as Anakin kills defenseless younglings. he’s anguished and horrified: the man he loved is gone forever. he goes to Padme, because he’s desperate to find Anakin, and that’s when his heart is truly and utterly broken beyond repair. this man he loved, the man he’d always loved, had never been his at all, and never could have been.
“anakin is the father, isn’t he?”