Right airpod not working

My right airpod only works when my left airpod is not in my ear at the same time. If I take only the right airpod out of the case and then use it, I can hear out of it. If I then take the left airpod out and put it in my ear with the right already in my ear, the right stops playing. If I then take the left out, I can't hear anything because the right still does not work.