What do I do?

My boyfriend and I are in a long distance relationship at the moment so once in a while we do stuff over the phone to keep it interesting. And phone sex is great and all... when your boyfriend doesnt finish way before you do. I have always taken a while to finish but the time difference between him and I finishing is long and awkward. He tries to last longer and I try to cum sooner but it just hasnt been working. Does anyone have any tips for what I can do?