So I'm flipping around the channels just now and see ISOYG3. Figured WTF since I saw the original a long time ago. Anyway I turn it on and there's a girl being followed by this dude down an alleyway. The exchange words, he slaps her around and then forces her to her knees. While he undoes his pants he says "Not just the tip" and I'm already laughing at this cheesy shit.
Then, all of a sudden, they show her with his dick in her mouth (prosthetic obviously) and she bites down on it. Then she Rams a knife through the cock and runs the blade to the base to butterfly it. Then she puts the finger of both hands through the hole and rips it in half and then begins to him in the sack about 12 times with the knife. After she spits the head of his dick at him she says "Not just the tip" and then beats him to death with a crowbar. After the scene was over I busted out laughing and literally said out loud "What the fuck did I just watch" LOL.
In any case, if you're looking for a feel good movie to watch with the family it seems ISOYG3 seems to be the one you're looking for. LOL.