When can you tell your boyfriend that your friend wants her to move with her to a different state?
Three options,a) Break up with him for some random purpose - girls seem to do that all the timeb) Tell him a few weeks in advance and hope he makes them the best weeks of your lifec) Not tell him, and ruin his year
Don't just let it be a surprise
Tell him before things get to serious. You don't want him to be so connected to you that he falls apart after you leave.
You could wait until you've already moved, guys aren't real bright, it might be fun to see how long it takes him to figure it out. Tell him when you've made up your mind and feel the time is right