Guy's Behavior

Why would my crush ge jealous of me hanging around another guy?

At this one dance my crush always kept coming around me a lot even tho he wasn't supposed to be near me or talk to me (cause his mom didn't like me at the time) but I ran into a guy I was friends with a couple years ago and I was talking to him when a friend said we'd make a cute couple I looked at my crush and he was angry after I moved away from my guy friend I looked other to see my crush right next to me I moved over because he was pretty close but he moved over even close staring a hole through my friend but when I went to walk away cause I was kinda scared why he was looking so angry at my friend but I heard him say something I turned around and looked a him and so didn't my friend but the came my crush right behind me

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+1 y
I suspected my friend of helping my crush so he could date me. Before dances she made sure he was going to be there and made sure I was going as well. At the dance she asked why I was acting differently towards him and I told her that i was acting like i didn't like him. Then she went and said something to him and he looked confused but then nodded and said he didn't like me. After that she dragged me around him and but when she went to walk away i watched her she motioned for him to come over
Why would my crush ge jealous of me hanging around another guy?
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