Our 13-year-old, soon to be 14-year-old, son teases his 9-year-old sister to no end. It causes our family a lot of strife. He teases her, she yells, lashes out, and then cries. I usually punish them both by separating them for a period of time. However, in all honesty, our son sets the tone and has driven the downhill spiral of the relationship. She used to adore him and forgives him quite easily. It's heartbreaking to watch, because she is so sweet-natured. We are extremely frustrated, and I am ready to remove everything from our son's room and have him work on his relationship with his sister to get things back. However, I am worried it will just breed more contempt. Any suggestions?