Can someone tell me why Tatiana wasn't allowed seeing MJ anymore?

that makes me want to cry and i feel really sorry for her and him i really dont think he ever had the chance to love who he wanted because of the people around him and that infuriates me i wish he would have stood up for himself or something but i guess he was just too shy but in the end i guess his entourage got their way they killed him and i wish i could change that im sooo sad r.i.p.