I feel the same :( but Rin should've had cared more about Yukio's feelings. Yukio actually tried to talk to him about how he wanted to know more about their mom and everything and Rin practically told him to shut up. They are both so silly, they both admitted they feel jealous of what the other one have and that makes me angry. How can you feel jealous of a sibiling! your blood! So immature
They are definitely both silly. But honestly I understand why Rin was so hesitant regarding their true past. He didn't want to confirm what he already knew about himself. The fact that everyone (Well almost everyone ig) thinks he's a monster. Seeing the truth with your own eyes hurts more than believing it on your own. I wish Yukio would just let down his guard already and accept that people love him.
I don't care how this comes off at this point but my reason for frustration is because I have siblings two of them are twins. Even though they argue about stupid shit for hours they love each other and would never let anyone hurt the other. So it saddens me to see Yukio doesn't give Rin the love and compassion that Rin gives him.