I swear I didn't say that

I gchatted Mikey yesterday from my parent's house. The conversation went something like this:

me: you up?

2:11 PM Mike: yeah

 me: good nap?

2:12 PM Mike: not yet(This is where I switch to another window, the recap of Oprah's season finale if you must know. . . I'm not sure I've ever watched an entire episode of Oprah, but after all the cyber-hubub about how great it was I had to do a little "research.") When I click on my gmail tab I see that I have written:

 me: why not?This confuses me. I don't remember writing that. But I was thinking it when I saw his reply about not taking a nap yet, so I didn't think much of it. Then I start looking through JCrew's clearance items on another webpage.

 Mike: i just got home and was reading

2:13 PM me: that's goodI switch back to gmail again and see that I wrote "that's good" and still, I have no recollection of it. I think, So weird. I must be loosing my mind. Then Mikey lets the cat out of the bag.

2:14 PM Mike: do you ever feel like someone else is writing for you on gchat?

 me: no why?

2:15 PM Mike: i dunno

 me: you're so weird
Apparently I had also left my gmail open back at our place, so Mikey decided to play a little trick on me. Want to know how much of this conversation he had with himself? All of it besides: you up? good nap? and you're so weird.

I was so confused. And then I got the giggles uncontrollably after he kept inserting himself into the conversation, posing to be me again and saying thing like, "you're so handsome. and thin. and tall."