蓮子ちゃんはきっと大盛を頼んで食べ残すタイプだから「メリーのオナニーが見たい！」って言ったのは自分なのにすごく恥ずかしい思いをするよ

Renko-chan is surely the type to order a large serving and then leave some leftovers, so "I wanna see Merry masturbate!" embarrasses her even if she's the one saying that.