My Girlfriend's Brother and I Goes to the Park

I'd been with her for about a year at that point so her family knew me pretty well and her brother enjoyed my company. There was a school autumn break that week so all the kids were at home so that means my girlfriend's brother was home too. I noticed he was swaying back and forth in the light and had his mouth open, drooling with a blank look in his eyes. This man made me feel really uneasy and I picked the little brother up and kept checking on this guy the entire time. He started groaning. It was almost pitch black at this point so I was using my phone as a flashlight. A notification popped up on my screen and it was my girlfriend