You participated in a mission by teaming up with Leon, you thought Leon was going to drink alcohol during the mission but was quite professional during the mission sometimes nice.

At the end of my mission when you arrested Glenn Arias you haven't heard from Leon anymore maybe he went on vacation.

You come home from a tiring day at the BSAA, you feel a pat on your shoulder, you turn and see Leon “Huh.. hi, it’s for you” he said, handing you a bouquet of flowers, which he had made himself.