I met the band afterwards, asked justin what his tattoos were.
*points to underside of right forearm* "this one says 'nevermind'".
*points to left wrist, at W.W.M.D. tattoo, above the red star* "this one stands for 'what would mom do'"
*points at ring-finger tattoo (two thin blue lines with green diagonals)* "...and this one stands for 'never let a bitch ruin your life'."