Paul says you do you
People can do what they want and they only harm themselves. The problem is when they harm others by approving of what they are doing: "God’s righteous decree that those who do such things are worthy of death, they not only continue to do these things, but also approve of those who practice them". (Romans 1:31)
People can do what they want but in no way should be give them our approval if what they are doing is harmful to themselves. Paul tells us MANY are weak and sick: "For anyone who eats and drinks without recognizing the body eats and drinks judgment on himself. That is why many among you are weak and sick, and a number of you have fallen asleep. Now if we judged ourselves properly, we would not come under judgment." (1Cor11:29,30) Paul said many are weak and sick and the word MANY should cause us to pay attention to what he is saying.