Complex sentence: After a particularly nasty fight between Tommy and Dil over Tommy's teddy bear, Stu has a conversation with Tommy about being a big brother and the responsibility he now has, assuring him that one day he will be happy to have Dil as his little brother.
Split into simpler sentences: After a particularly nasty fight between Tommy and Dil over Tommy's teddy bear, Stu has a conversation with Tommy about being a big brother and the responsibility he now has. Stu finishes it by assuring him that one day he will be happy to have Dil as his little brother.