TL;DR: He says there something like "Yes. I understand it perfectly".
Longer version aka summary: Edward (glasses guy) wants to take Otowa with him to England, Otowa isn't sure about it because of Zen. Then Zen admits that he really did everything to kill his father and then get his revenge on Otowa, but he fell in love with him. Zen says that he doesn't want to see him and Otowa decides to go with Ed to England. He wants to disappear, so he won't cause Zen pain anymore. Takao tells him that he should pray for a safe trip at a local shrine, so he goes there and eavesdrop on Zen praying for the same thing. Then then talk, Otowa says he loves him, they do the do in the shrine, plan to run away together and that guy attacks Zen in revenge, bla bla bla. Otowa runs to Ed to ask for help, but he sees the lovebites on Otowa's neck. He says somethings like "Asking for help in a situation like that... You understand what it means?" and Otowa answers "Yes. I understand it perfectly" (it's the scene you linked). So they go to help Zen and Otowa goes to England with Ed in exchange. But then he comes back a bit later saying that Ed gave him a divorce, because he had enough of Otowa talking about visiting Tsubakirou. Otowa jokingly asks Zen if he can work in the brothel again, but the man says something like "We don't want weirdos here" and they bicker for a bit. Then there's the "never leave me again" and "welcome home" talk. The end.
Sorry, it's not really short and might be hard to understand XD
http://www.mangago.zone/read-manga/chinrou_cantarella/raw/raw-chapter-286525/37/ Can you say what Otowa says to the boy who wants to get him from brothel? or maybe short summary of 5th chapter.