If my wow account was active i could try it right now with SC2 and wow. Trying to remember if i ever did have both running. I think i did, but i'm not certain.
I know you can have multiple wow accounts on the same battle.net that are running at the same time.
Sharing the account info is not permitted, but if you log it in, and he plays on it, that is actually allowed, because you didn't give him the info. Both being in the same physical location is the only way to ever actually do it. Call up Blizzard and ask, but i believe that was the case. Again, you aren't sharing the account info that way.
like i said i'm not certain, but i think i did it once, when i was playing SC2, and my son needed something in wow. so i tabbed out and popped on.
And i would definitely call Blizzard and ask, just check with account services. It should be a 5 or 10 minute hold time, for a simple yes or no question. Worst case the person has to put you on hold to go ask his/her lead. Worth knowing the answer rather than risking your account.
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