Q: While a friend is in jail.

[The Legendary Joe]

It would be fine, so long as both of you are there to respond should a GM pop up to check to see if it IS actually more than one person playing. In short, Don't go AFK if both computers are running the game.

If not, people would start getting the Ban-hammer. It would look bad, and most explanations would end up making you look even more guilty.

I think the best way to get through Jail time is to leave the Jailed character logged in, and AFK'ed in jail while you yourself goes out and Parties IRL. So long as it isn't auto-vending, Every hour you spend boozed up is one hour closer to Mr. Moneybag's Freedom.