"I want you to be having a good time too." Erwin lies back without complaint, but feels the need to explain himself as he lowers down to the mattress. "This has been all about me so far."

Is he too hung up on dicks? Yeah, probably. Erwin learned about sex in a certain way, and the fact that Levi hasn't responded to him in the way he expects is baffling. He doesn't want this all to be for his benefit only!