I don't think they did. Freddy wanted to get away, and Gabe wanted to talk to Sasha, so it suited him fine to send Freddy out to find Richie. If Gabe was in any way a proper friend with a clue, he would have told Sasha he had guests, and he'd call her back tomorrow - or failing that he would have stayed away from the tree house till the two guys came back in. Gabe is selfish and smug, and if Richie wasn't so desperate to keep his only friend, he'd call him on it.
Freddy had no right or reason to tell Richie his father loves him. I bet he never heard Richard say that, and no normal teen would be able to come to this conclusion on his own. This is just the author channeling his superior knowledge through Freddy in order to get to Richie. It won't work with me, since the abusive, manipulative, egoistic bastard hasn't shown any love or consideration (recently) by actions or explanations.