make me understand (=・ω・=)

Basically Eren feels obligated to not tell Levi his feelings so as not to burden him because he believes Levi will have to kill him eventually. As for Levi, I think him having sex with Eren is his way of telling Eren he’s still alive. Either way, it’s a vicious cycle that continues to spiral out of control because bother refuse to actually communicate their feelings. Hope that helped