You hit him in the balls by accident *request*
Harry: You were running around the backyard after your cousin with your boyfriend Harry. It eventually turned into a game of tag and you were it; both your cousin and Harry were hiding and when you found Harry he began running. You finally got in front of him and stuck your leg and arm out spaztically to tag him and he immediately ran into your leg, hitting his groin. He screamed and hit the ground clutching his manhood with his eyes squeezed shut. You covered your mouth to keep from laughing, "Babe! Are you okay?" He kept his eyes closed and nodded quickly, "I'm fine." he said in a high-pitched voice. You couldn't help but burst out laughing and kissed his forehead while your cousin was rolling around on the ground from laughing so hard.
Liam: He was chasing you around the flat trying to tickle you and you began to push obstacles in front of him to stall him from getting to you. You pushed a chair, a small table, and knocked a movie stand over to keep him from getting close. While trying to get to the bedroom you moved a lamp stand and he ran into it; the lamp hitting his groin. His knees buckled and he fell over, his head hitting a nearby pillow. You ran over completely worried, "Liam!! I'm so sorry!" you yelled, trying to help him up. He coughed a couple times and took your hands, yanking you down with him as he began to tickle you. You started laughing and kicking your legs trying to stop him when you kicked him in his crotch, he yelled and buried his face in your neck. "I'm sorry!!" you yelled, trying not to laugh. He just shook his head quickly, "You're lucky I like you!" he said into your neck.
Louis: You were playing football (soccer) intensely in your backyard. It was your turn to kick the ball and you both stood in front of each other looking deep into his eyes. He smirked, "Don't mess up, babe." he said. You narrowed your eyes and kicked the ball as hard as you could and he immediately fell to the ground. You were confused until you looked down and saw the ball hadn't moved. You had missed and kicked him in the balls by accident. You fell to your knees and put a hand on his cheek, "I'm sorry!!!" you yelled, your finger smoothing his cheek. He was trying not to laugh and you lowered your eyebrows, "What's so funny?" you asked, sounding upset. He shook his head and chuckled, "Remind me never to let you play professionally."
Niall: You were sitting on his couch with him as he tried to teach you how to play guitar. He placed the guitar on your lap telling you which strings to strum when you got frustrated. "I can't do it, Niall." you said, sighing. "Sure you can!" he said, smiling. "It's simple!" You rolled your eyes and put the guitar in his lap and he put it back in yours. Irritated, you did it again, and he did it right back. "Stop, Niall. I don't want do play anymore." you threw the guitar into his lap and walked away, irritated. You heart a grunt and a thud and spun around to see him curled up on the couch cupping his manhood with his eyes shut with the guitar on the floor. "Shit!" you said, running to him. "I'm sorry!" you yelled, helping him up. He put his arm around you and stood up, "It's.... okay, babe." he managed to say, coughing a couple times. "We just... need to find you.... a new instrument to play."
Zayn: You two were dancing like idiots for one of his new dancing videos. He was trying to do the sprinkler while you were dancing to something from High School Musical. He got too close while you were trying to spin and your foot hit him straight in the crotch. He made a loud 'peep' noise and feel to the floor, cupping his groin. You looked at the camera panicked, "Oh my god, babe! I'm so sorry! Are you okay?" you yelled, kneeling down. He cleared his throat, "I've been better." he said, high-pitched. You began to laugh and when he looked up at you serious you stopped but started up again. He tried getting up and gave up soon after. Later that night you uploaded the video and #RIPZaynsTesticals was a trending topic about ten minutes later.