Vespian tends to act the same on the forums as well as in the actual game. Although, there are some minor differences.
On the forums, me guesses ye can say I'm much more outspoken and prone to conversation while in the game, I'll hardly utter a word less addressed directly. Whether in-game or on the forums, I use my own collection of slang (that apparently makes I sound like a pirate?) and punctuation. There have even been some instances where I'll partake in tumblr speak, though scarcely.
Not much of a difference regardless. Vespian acts like Vespian through and through no matter what program or tab may be open.