Why do I get so mad at the guy I like?

so long story short...im 15 and my neighbor is 21...hes really cute and i have a huge crush on him lol. Well his family adopted a chinese kid awhile ago, and now the chinese kid is 9 years old and hes really bratty and annoying, and thinks he rules the world or something. Well my sister and i were playing basketball and the chinese kid was there because he always comes up, and then my crush came up and said he was there to get the kid. All of a sudden my crush was like "there's something missing" and started tapping his shoulders. he was like "i dont know what it is..." then all of a sudden he lifted the chinese kid up over his head and plopped him on his shoulders. then he was like "ahh that's better." Well my sister was laughing but for some reason i felt something really weird. Like anger or something. I mean that little brat should not be riding around on my crush's shoulders like he's a slave or something. and to make things worse the chinese kid was all like "this is more like it." and stuff. why do i feel so mad???