AFTER I TOOK OFF MY TIARA CHAPTER 79
When Istel's cry was not visible again. He felt better and he also wouldn't know how to ease her pain if ever she cries again. It hurts him, but her cry makes him vulnerable to think anything.
Earlier, he felt that he was about to cry when he saw her cry but couldn't do much but to say encouraging words to her. He doesn't know whether that was enough to cheer her up, but looking at how her expression had brightened up, he felt happy. He knew that he did nothing much, but at least, he did his best.
He might not be good at expressing himself through words, but he did his best. Also, since it was definitely the first for her to cry over his happiness of them having children, he was stiff on comforting her.