"Perhaps a tiny bit," Remus admitted, arm tightening briefly around Regulus for a moment. Perhaps, more than jealousy, it was simple acknowledgement that he was incredibly lucky to have Regulus' affection and Remus was well aware how far out of his league Regulus Black truly was.
"My concept of taking it easy is a brand new concept to me," he pointed out, silently casting a privacy spell to ensure there were no repeats of before. He didn't want a full audience for what he was about to say. He might have no choice about being in the hospital wing for this, but he could control that much since he didn't think he could wait another day to tell Regulus. "It's been a long time since I've been able to let my guard down enough to take it easy, since I had the luxury of being able to slow down when I'm not fine or when I'm in pain." And his friends had a tendency of simply just accommodating his stubbornness, letting him push through, because they were as terrible about it as he was, which meant it was probably a Gryffindor trait as Regulus said.
"However," he continued, nuzzling at Regulus' temple, "I seem to have fallen in love with a Slytherin who is inspiring me to learn how to take care of myself because I would like to be by his side for a very long time, though it seems I have to be separated from him tonight. And I mean this very seriously." Touching his fingertips under Regulus' chin, he gently tilted the younger man's face up to his. "I love you, Regulus."