Is dancing with an ex cheating? ?

I have been with my boyfriend for a year now. He recently came across pictures from the beginning of our relationship where it looked like me and my ex were dancing. He is grabbing me at the hips and we were both smiling. I'm at a loss at what to do because I honestly love my boyfriend to death he's amazing and he's so upset I'm sure he won't be around much longer. Keep in mind he HATES my ex. it's so painful to hear how he feels about me now. Is he justified in breaking up with me? Am I really a cheater? Help me please!!