On New Year's Eve, my boyfriend kissed his best female friend on the lips. Yes - ON THE LIPS. I was shocked and couldn't believe he literally cheated right in front of me. I mean I was standing right there. He kissed and hugged me - then walked across the room and kissed her!!! He said the kiss wasn't cheating because he's been doing it for 7 years & she is like his sister. It meant nothing. He says I am over-reacting. I left the party early that night obviously. He says it really was just a friend to friend kiss. So am I wrong? Was 'the kiss' cheating or not?