The trap... Got him right there. And lost all the control that still had left to struggle and keep his reason in check to not give up himself into pleasure. Things may escalate out of hand, quickly, already. No more space to get back, poor little bro (or lucky). Thankfuly, there are a lot of tenderness and love between them. Which may as well be his own ruin, overflowed by it, not giving room to think about anything else other than love, milk, breasts and his big sister. His life may acquire a new porpuse, like it or not.