you cheat and there will be consequenses. Why do I use the friend-spell? I really really want the the knowledge from that one NPC and my charisma to get it is not high enough. So I make him friendler towards me for awhile and maybe he tells me because im he's best chum. Afterwards when spell ends he will know he got cheated. He would never tell me those things. Of course he gets angry. I would be too. You made a choice to 'cheat' him out of some knowledge.
