Is it illegal to like your brothers friend whos 18?

Answer 1

The question is: Is it illegal to like your Brothers' friend who is 18 years old?

I am assuming you are referring to the word "like" to mean sexual attraction.

If this is the case, then it is not illegal in the literal sense to be sexually attracted to anyone over the age of 18 in most of the United States and Europe. In some regions it would be OK for the object of desire to be 16 or 17.

However, for an 18 year old to be sexually attracted to someone who is, say, 15 and then act on that attraction may be breaking a law.

However, if I am to take your question in the literal sense: No, it is never illegal to "like" anything or anyone in most free countries. Of course, this rule would not apply if you were living in Iran or Afghanistan where if you were to "like" things like homosexuality or anything that goes against their Theoacracy, then you would be put to death or imprisoned.