Why did you bother to let him know that?
First off he is an unbeliever.
Therefore, the goal is for him to become a believer.
Technically, he could become a believer and still practice homosexuality (not everyone may agree with this) Or, he could stop being a homosexual and then become a believer, or he could stop being a homosexual and remain an unbeliever.
I see no benefit for him to stop being a homosexual and remain an unbeliever. It may be a beneficial choice for him health wise, and in some other ways, but it would not give him eternal life.
From his perspective the homosexuality is creating a road block for salvation because he thinks that he has to stop being a homosexual first in order to become a Christian. Therefore, the homosexuality is destroying his life because he doesn’t want to give it up for the only thing that can save his life.
I once knew a girl who had lived with a guy for years (they were not married). She said that she would never ever go to a church because they teach that living together is a sin, and she wasn’t going to move out because she loved her boyfriend too much.
So, some people like what they are doing too much, and don’t want to stop doing what they are doing.
I see nothing wrong with letting them know that this sin that they are “enjoying” is destroying their lives.
Some get angry, some say I preach hate, and some get really sad, but at least they are told the truth. I can’t worry about how they are going to react to the truth.
It’s a process, every individual, and every circumstance is always different. There is no blueprint for success. Some repent and become saved in a few weeks, some take years, and some never do it.