Why would a guy friend get very nosy about your personal life?

[Anonymous]

He keeps asking me questions about my other guy friend all the time with whom I'm much more closer than him. Whenever I talk about this guy friend of mine he clearly displays jealousy and then asks a lot of questions about him i. e. invading my personal life.

This week my other guy friend attended Math class with me and he was sitting with me so my guy friend started acting mean with him for no reason and was even chuckling when he gave the wrong answer.

He's really creeping me out now. This week, our Math teacher was giving me an awful lot of individual attention (he acts very obsessive with me too) so my guy friend got jealous and quickly said "Woah, you've got all the teachers wrapped around your finger haven't you?". What he meant by all is that our English teacher gives me an awful lot of attention too.

Yesterday around 3 am, I was missing my first love a lot so I posted this quote about how love fucks you up real bad and he instantly responded to it within minutes saying "Oh is that so?" with sarcasm. This is not the first time he's viewed my updates at odd hours.
What's up with him? Why is he suddenly acting all clingy and nosy? Should I be worried or not?

[Nob0dy]

He loves you. So far when he was just your guy friend he had no problem, but, now that he could see that you're slipping away from his fingers and might end up being someone else's girlfriend, his love for you has awakened and he's so terrified of losing you. I'd say he's madly in love with you so, next time you see him, confront him with this, "I will ask you this one question and you'll have to chance and only one chance to reply with a yes or no, are you in love with me?". However you will respond to him is up to you.

[larry69]

Block and report him to school admin. Thatsharrassment and stalking. That guy is no friend

[Asker]

Why do you say he's no friend?

[larry69]

If he was a friend then he would not be so jealous of you had another boyfriend. He would not be following you at all hours of the night. K think he's obsessed.

[DublinRollerGirl]

Come on, wake up. your friend has feelings for you but never spoke up because he thought it would ruin your friendship. He is just jealous that someone else will be taking his place. This happens a lot with male/female friends.

[Aspiringdr]

He likes you, but in an emotionally unstable way. You do not want to be with a guy like that. I’d try to distance yourself because I can imagine it getting worse

[_dardorsama_]

Easy

He's obsessed with you

[Asker]

Why so you say he's obsessed?

[Asker]

*do you

[_dardorsama_]

Because he's placed you under a microscope

How else he replied right away when you post late at night

[introvertedindian]

M 90% sure he likes you
But dont know how to express it

[Tomblebee]

Do you like the guy you are closer with?

[Stylish27]

Maybe he's interested in you...

[Kayla45]

maybe he has a crush on you?

[NaughtyBoy777]

He obviously has strong feelings for you.

[dp101]

if he’s straight, he likes you.

[Anonymous]

If he's just a guy "friend", you wouldn't care