Why would Penny's father who disapproves of Desmond tell Desmond were Penny Lives? I think its all part of an experiment and Desmond is the mouse in the maze.

i think Mr. Widmore was pretty confident that Penny was over Desmond at this point... that she could get rid of des easier than he could himself...

I have said from day one that he is her pawn in some sort of experiment. After last night it looked like she really liked him but things are never what they seem in this show. I still don't care much for her.