Switching audio between computers

[Stillwatrpwnage]

Hello!  I recently decided to get synergy and I was wondering if anyone knew of any similar programs that would allow switching which computer my bluetooth headset is connected to.  I like being able to have a video playing off to the side on my laptop but my desktops monitor is my main monitor and being able to switch between the two would be very useful.

Or a program that allowed connecting to both at once, that would honestly be ideal but I can't connect to the other computer until I disconnect from the first one.

 

Edit: I'm essentially looking for a way to mix the two inputs and send the output through bluetooth.  I'm aware a mixer can take two cables in, modify the volumes, and have a single cable output and that would be a beautiful solution but I use a fairly high quality bluetooth headset so I don't have a cable getting in the way and I can get up and do things around the house without having to disconnect from music, youtube, netflix, etc.  I've been looking into this for a couple days and haven't found anything, I'm hoping there's a software solution, which is why I mentioned synergy, but I'm completely willing to invest in some hardware if it solves my problem.