¨No¨ is a Spanish word, is a Negation expression. In Spanish this word is commonly used in questions to claim or ask for an affirmative answer or is used too in way to express doubt. It is used as a negative response to a question; it is used as an expression of rejection or non-conformity.

¨Es¨ this Word in Spanish comes from the verb ¨to be¨ used for third person, in the following example has the same meaning as ¨is¨: She is so beautiful.

¨Justo¨ is a Spanish word with diverse meanings. It is a person who acts according to the justice, the moral and the reasoning. It is also related to something that is deserved: Fair prize. ¨Justo¨ also refers to acting as it should.
This word is sometimes used to refer to something that is narrow, like clothes. It means something measured precisely, the perfect amount of something.
In medieval times ¨Justo¨ was a kind of fight or combat on horseback and with a spear.
¨No es justo¨ this sentence translated to English means ¨It is not fair¨, it refers to something that is not fair for some reason.
There is a reggaeton song with this name ¨No es justo¨, a song from J Balvin a famous Colombian reggaeton singer and Zion & Lenox a famous Reggaeton musical duo from Puerto Rico. The lyric of this song talks about the attraction and desire who can feel two people between them. It is about the desire, passion or the feelings that another person can make you feel and it can’t be hidden or stopped, it is something that you mind can’t control. Furthermore the song talks about this woman who has an amazing skill to dance, she is sexy and beautiful so It is not fair that she is incredible beautiful. Its beauty becomes a weakness for this man. Basically he just wants to follow his emotions and desires then he wants her to follow her emotions and desires as well. By the way, he is pretty sure that exists a feeling between them, he can feel it due to the way she looks at him. He feels really attracted by her and the feeling is making him crazy, he wants her badly and that’s not fair because she doesn’t dare. Finally he tries to say pretty things to her and he knows she likes it, so he's going to keep trying to convince her because is what he really wants.