You guys were in the Sumeru library reading a book as Al Haitham looks at you.

"So. How long has it been?"

He obviously wants to talk to you. Most of the time he hasn't had enough time for you and he feels about enough about it

"I; uh. I've missed you."

He puts a bookmark into the page he was reading and looks at you with a pokerface. Although his cheeks were turning into a bright red.

He cleared his throat as he was clearly embarrassed about his words.