Spike was just focusing on having fun himself and wasn't worried about what was going on around him so he missed the whole dude coming out like the tube monster and scaring the girls. He tried to stay to himself most of the time anyway.
He couldn't do that though when he felt someone take hold of the back of his swimming trunks. He wondered who would be daring enough to grab at his ass and he spat out the water he swallowed when he was caught off guard. He didn't have to look to see who it was though as only one person was going to get away with calling him fuzzy.
He chuckled as he wiped the water from his face and turned to face Johnny. "Trying to drown me already? And you thought I was the dangerous one."