He is stalking Yuri, it actually becomes a problem because Yuri doesn't want to be stalked but Jake thinks he has to check on her to protect her because of people like Peacock...and his sister, because he's still convinced she loves Ian and plans to attack Yuri later on for Ian showing interest in her.
He has absolutely no respect for his sister and just expects her to show a bully side at all times, well, he also just happens to like Yuri and is a stalker, but uses the "protection" defense to justify it even though Yuri didn't request any protection and doesn't like being stalked.
Funnily enough, it's one of the main reasons if not the main one why Yuri doesn't care for Jake, without Melissa being a bully for them to save her from, Yuri can just interact with the guys as they really are and just naturally finds them to be jerks or not that great, they all depended on Melissa being evil to actually be love interests, without that, Yuri just thinks they are obsessive creeps that are also jerks and not as cool or awesome as Melissa.