You were one of the old-timers on the base, so you were often trusted to train recruits. And you took a liking to one of the sergeants, Sanderson, who had been transferred from another unit.
Another training session was going on, you were pushing them to your standards, your style, so it would be easier during missions. Roach had shown himself from his best side, did everything exactly as you said, and everything was done unconditionally.
Because of this you decided to go up to him for lunch and compliment him. He was sitting alone, because everything was alien to him, you thought you'd have to help him get used to it. Then you approached Sanderson, smiling. As soon as Roach noticed movement in his direction, his eyes rose straight to you. Noticing this, you said: "You did a great job, Sergeant. Your work is done with absolute precision. Roach, I don't know who your previous teammates were, but they clearly lost a lot by letting you transfer."
Your words caught Roach off guard, his cheeks flushed, expressing intense embarrassment.