The following was taken from the official website of the Jehovah’s Witnesses:
God created humans to engage in sex only within the arrangement of marriage between a male and a female. (Genesis 1:27, 28; Leviticus 18:22; Proverbs 5:18, 19) The Bible condemns sexual activity that is not between a husband and wife, whether it is homosexual or heterosexual conduct. (1 Corinthians 6:18) This includes intercourse, fondling another person’s genitals, and engaging in oral or anal sex.
While the Bible disapproves of homosexual acts, it does not condone hatred of homosexuals or homophobia. Instead, Christians are directed to “respect everyone.”—1 Peter 2:17, Good News Translation.
It is worth noting that the above is an only one interpretation. An interpretation based on their own views. If we deconstruct the passages referenced above highlighted in bold, we can soon see that homosexuality is not actually referenced in the way it is first suggested:
Genesis 1:27, 28
27 And God went on to create the man in his image, in God’s image he created him; male and female he created them; 28 Further, God blessed them, and God said to them: “Be fruitful and become many, fill the earth; and subdue it; and have in subjection; d the fish of the sea and the flying creatures of the heavens and every living creature that is moving on the earth.”
No mention of homosexuality.
22 “You must not lie down with a male in the same way that you lie down with a woman. It is a detestable act.
This is very loosely, possibly, inferring same-sex intercourse (but as this is not explicitly written, it can only be guessed or interpreted). Regardless, same-sex intercourse of course is not the same as ‘being gay’. Someone who is gay may, or may not, engage in same-sex intercourse - they are still gay either way.
Proverbs 5:18, 19
18 May your own fountain* be blessed, And may you rejoice with the wife of your youth, 19 A loving doe, a graceful mountain goat. Let her breasts satisfy* you at all times. May you be captivated by her love constantly.
Again, no mention of homosexuality.
1 Corinthians 6:18
18 Flee from sexual immorality!* Every other sin that a man may commit is outside his body, but whoever practices sexual immorality is sinning against his own body.
Homosexuality again is not referenced explicitly. It is inferred that one should free from ‘sexual immorality’. Sexual immorality is the judgement of another person’s sexual activity which is deemed to be ‘immoral’. This commonly refers to sex outside of marriage.
Alternative sources to consider: