Jealousy is cute sometimes, but this is obsession. That's why Hyuk says you're a kid because you're immature. Checking the MC's phone, blocking someone on your partner's behalf is envasion of privacy, regarless if that friend likes your partner, you should trust your partner instead, not blame the other party.
The only thing the readers like about him is because he's the ML of this story, but if you look at the picture, the MC's friend is so much better than him.