ANSWER:

Don’t look at the size of the sin, rather look at Who you’re sinning against! However, you already know this and hence, you have no regards to the fact the allah is watching you do such filth! Therefore, it doesn’t matter whether it is major or minor sin. 

QUESTION: Is masturbation and watching porn a major or minor sin? I know it is not recommended to see the size of the sin but have to see whom we are sinning against. But this is for informative purpose. Please answer Sheik