Board Thread:Questions and Answers/@comment-35743423-20180531145949/@comment-26415426-20180714212123

I always kind of assumed Jughead did tell him or FP figured it out. FP was angry because he knew how dangerous Penny was and he told Jughead to stay away from her no matter what. He did so much to protect his son, landing in prison because of it, and then his son still ended up in danger.