, 04:49 AM
If we want to take the recent Clone Wars series into account (which it seems everyone is) I am 100% sure Obi-Wan knew.
While I am not sure on any specifics, I KNOW I recall a few telling looks or sidelong glances Obi-Wan shot Anakin/Padme on more than one occasion. And yes, we have the line in RotS "Anakin is the father, isn't he?" And, as Brandon mentions, knew about their love for each other by the end of Episode II.
Anakin: Put the ship down!
Obi-Wan: Anakin! Don't let your personal feelings get in the way!
Anakin: Lower the ship!
Obi-Wan: I can't take Dooku alone! I need you! If we catch him, we can end this war right now! We have a job to do!
Anakin: I don't care! Put the ship down!
Obi-Wan: You will be expelled from the Jedi order!
Anakin: I CAN'T LEAVE HER!
Obi-Wan: COME TO YOUR SENSES! What do you think Padme would do were she in your position?
Anakin: ....She would do her duty.
He is fully aware, he's just choosing to remain quiet about it.
The reasons why are also fairly clear; Anakin is like a brother to him. He cares about him, and even though he may have reprimanded him for it he wouldn't ruin Anakin's life as a Jedi by telling the Council. As Padme says to Anakin, Obi-Wan knew and "want[ed] to help," and I believe that wholeheartedly. ESPECIALLY considering this recent Duchess of Mandalore subplot. Obi-Wan's been there, he knows what it's like.
Actually, I find Anakin's actions even MORE infuriatingly stupid CONSIDERING Obi-Wan's past. He was willing to leave the Order for a woman; don't you think he'd understand your position? Of course, this all chalks up to "meh" writing.
Rayla_Felana, I'm not sure where you are getting your info from. It's stated time and time again that Jedi are forbidden from relationships. The ONLY exception I can think of for that time period is Jedi Master Ki-Adi-Mundi. A very special exception was made for him because of the odd sex ratio for his species, in order to ensure they wouldn't die out.