It is becoming increasingly popular for Christians who are abiding by the biblical sexual ethic to identify as gay in order to convey which sex or gender they are attracted to. They use this term to identify their experience with their sexuality. I understand this and certainly don’t think the use of this term is inherently sinful (though it can be confusing). However, as with anything, there is a chance sinful desires could be underlying it. If that is the case, the underlying condition of the heart ought to be the main focus of exhortation, not the external language used.
Personally, my conscience does not allow me to refer to myself as a “gay Christian.” Rather, I refer to myself as a Christian who is same-sex attracted. This term is accurate in describing my experience without causing ambiguity. For me and my conscience before God, referring to myself as gay would constitute a hint of sexual immorality, as many people might make assumptions about my life and holiness based on that term.
To use a different example, although I enjoy visiting breweries and trying different beers (in moderation), I would not refer to myself as a “bar hopper” or “pub crawler” because those terms may convey a misguided perception about a lifestyle that goes against the central core of my identity, my devotion to God. Similarly, if I were to use the term gay to describe my experience with my sexual identity, it could give the wrong impression about my lifestyle. It could suggest that I am living in a way that directly contradicts the most central and foundational part of my identity, Christ.
Therefore, in order to remain above reproach in this area, I use the term “same-sex attracted” to communicate my experience with my sexuality. I do not use this term to celebrate this part of my identity as a central and foundational part of who I am. My love for God and devotion to Him are far more central and foundational to my identity than my sexual attraction.
However, if your child or loved one is a Christian who abides by the biblical sexual ethic but refers to themselves as gay, I do not personally think this is a hill worth dying on. You may ask your child to consider the implications of their word choice, but ultimately the condition of their heart will determine their righteousness, not necessarily which term they use to describe their experience with sexual attraction.