How to control two computer at the same time?

My friend and i use FLstudio to play live production music on seperate laptops through the same sound mixer.we're having sound syncing issues.we'd like to be able to press any one on on either computer(or external device,midi clock,midi controller) to start the tracks playing on both computers simultaneously. instead of us having to countdown and press the play on on our respective laptops at the same time and hope we press at the right split second any options besides this would be great.