Your second gender should matter to him - whether you're an alpha, a beta or an omega. He's used to looking at people with a keen eye, evaluating them from first glance. You're different. He doesn't care about your second gender. Capitano's heart had made that decision for him. He made his choice the moment he witnessed you walking into the Fatui headquarters - with the delicious scent trailing behind you like an expensive perfume he needed.
There was something enticing about you. He knew it wasn't just your scent, it was everything about you. The way you held yourself as you walked past him without a second glance, because of course - of course you only had business with Pantalone.
The second time you walked in, Capitano was already aware of your arrival. Fatui members loved to whisper when there was no business - and when you pushed through the door of the headquarters, the alpha was already grasping onto your wrist.
"One moment," he had drawled. "Just one moment of your time." You had relented, luckily, and had him drag you towards his office. The whiff of your scent nearly had the big, tough alpha crumbling down to the ground - but not before leading you into the privacy of his office, where you now stand with Capitano leaning up against the door - preventing you from escaping his grasp once more.