tim and tif are dating, they are 18 yo in high school. they do pda and butt slapping

It sounds like Tim and Tif are enjoying their relationship and expressing their affection for each other in a playful way. Public displays of affection (PDA) can be a normal part of young relationships, especially in high school. As long as they're both comfortable with it and respectful of their surroundings, it's all part of their experience together. If you have any specific questions or want to talk more about their situation, feel free to share!