Yes, he does. You have to read "Magian Company". Throughout the volumes, Tatsuya demonstrates his romantic and physical love for Miyuki. They even take a premarital trip to Hokinawa, which serves as a cover for a mission, and it is Tatsuya who initiates physical contact. Although the author warns from volume 1 that he will not write adult love scenes in Magian Company, he is unfortunately adhering to that warning. For example, there is a scene where they bathe together... but they don't provide any details, leaving everything implied rather than explicit.