simplify
First to answer your question:
How do you know they are acting simply on sexual urge or lust or because it feels good unless you are that person feeling what they are feeling, experiencing what they are experiencing.(?)
Thomas, my friend, that's my point, you're not acting simply on 'sexual urge or lust', you could do that naturally and normally through sexual intercourse with a person who has a reproductive system (thus, sex organs) that couples with or compliment yours. You're acting on a mental condition or disorder that no one understands - not even yourself. If you were honest with yourself you would admit that you don't know why you do what you do rather than try to convince others that you are simply a gay person (being) and that your behavior is perfectly natural and normal.
It's probably a difficult life for you as you seem to feel some sort of frustration in my opinion of your behavior. (Please note: My opinion is not of you as a person - I don't know you personally). And I think you would be a prime candidate for a good treatment program but first you will have to come to terms with your condition or disorder. Like a person who is suffering from an addiction, you have to admit that you have a problem and others don't have to accept your problem so that you can feel good about youself.
Man, (woman, boy, girl, person, whatever you are) I don't hate anybody on this earth. Quite frankly I sympathize with those who indulge in your particular type of behavior. But I also see it as being wrong and improper. And, please don't tell me that my opinion is based on my religious beliefs. They are not - they are based on how I see things fit. And male to male and female to female just don't seem to fit properly to me.
Man has been on this planet for more than 200,000 years and has managed to procreate his own kind through natural and normal sexual intersourse. No one knows how long homosexuality has been around but it is a known fact that such behavior reproduces nothing. That is why, in my opinion, it's done strictly for some sort of thrill.