Sat Nam and Greetings to all!
Obviously, this question has struck a chord in many. Any question having to do with sex and sexuality will of course be of concern.
When ever I find myself confronted with anything that could be controversial within my thoughts and feelings about it, or controversial between my views and someone else's, I have always found comfort in what Guru Nanak Ji said, "If you cannot see God in All, you cannot see God at all."
That being said, here are some thoughts on this topic.
Sex is, of course, of concern for obvious reasons. Anytime anyone wishes to engage in sexual practices it is ideally in a responsible manner, and it is not something to be engaged in or thought about lightly or casually. We all know the sad consequences of promiscuity(regardless of orientations or genders involved)- the unplanned pregnancies, the transmission of diseases, the psychological damages, and the commodification of human beings into objects, to name a few. As regards homosexuality, one way to really explore just exactly how you feel about it, and how you think and feel about it in relation to Sikhism and religion in general is to engage in a mental exercize and pretend that one of your siblings, or one of your best friends, or other relative, has just told you that he or she is homosexual. Then see what your thoughts are, and how you feel.
This really did in actually happen to me. One of my cousins told me she is homosexual. She is also a devout Christian. She was very hesitant to tell me. I hugged her and asked her, "Why did you feel so reluctant to tell me? Did you think I would stop loving you? I will always love you, you are dear to me, and I want for your highest good and happiness in all ways!" She told me she was so happy to hear that, but that she was worried about what the people in her church would think. I told her that her relationship with God is the First Relationship, and that my feelings about that matter are that as long as she has the relationship with the Divine as her most important relationship, and stayed in close contact with God always, that all other matters would be taken care of, and she need not to worry. I told her about how we Sikhs are to keep Nam Simran, and that she might think about doing the same. This was 2 years ago, and she is doing well, and does her own Nam Simran, in a Christian context. Interestingly enough, about a year ago, a Sikh lady told me she was homosexual, too, and was also hesitant to say anything to anyone. I hugged her and told her much the same thing as I told my cousin, that the Relationship with God and Guru is the most important, and reminded her of what Guru Nanak Ji said, and she was very much happy with that. So, it is a delicate subject indeed, but on a very personal level, I cannot not love someone and I cannot condemn anyone just because they are homosexual... indeed, basically everyone is a brother or sister of mine in the eyes of the Divine, including anyone reading this, and, as my cousin would say, We are all God's children anyway!
Blessings to all,
Kulwant