I EXACTLY HAD THE SAME PROBLEM AND I BELIEVE I STILL DO. MY BROTHER IS ALSO DATING A GIRL WHO I SLEP WITH COUPLE OF YEARS; AND WHEN I DUMPED HER, SHE STARTED TO SLEEP WITH MY BROTHER. I TOLD MY BROTHER ABT THIS; HE DIDNT BELIEVE IT AND THEY CONTINUED AND STILL ARE, I GUESS. NOBODY KNOWS WHAT GIRLS REALLY WANT. I WOULD SUGGEST TO GO AND TALK TO UR BROTHER ATLEAST. I THINK HE DESERVES TO KNOW THE TRUTH AS HE IS UR BROTHER AND I AM SURE U WILL TELL IF U CARE ABT HIM.