isfb 

Internet shortening for "Im so fucking bored"

screenname1:isfb.
screenname2:me too, wanna see a movie?

isfb by seanifukin3 March 23, 2009

ISFBG 

I Should Follow Back Guilt - twitter's newest psychological disorder. You follow everyone that follows you.

Oh cool, this dude is following me. I feel ISFBG, and should follow back, i don't want him to (unfollow me) feel bad.

ISFBG by errorid May 4, 2010