It's the smell that hits him first and holds him awake, then the texture... and then the taste. Scout opens his eyes to the dog licking its shitty vomit off his face, trying in vain to push it away and get it to stop, spitting out whatever he can and gagging. Once enough space had been put between them, he wipes whatever he can off with a hand, now even more disgusted... but also waking up with wood and while still half-asleep doesn't really think twice before using the vomit as lube to jerk off. Maybe he's used to having a morning jerk-off session before getting out of bed to deal with morning wood, and today is no different. The dog just stands there watching, or maybe it throws up a second time, this time onto his dick.