I can counter your argument by saying simply: A homophobe would only have to see the same thing you do (the men kissing), and would draw a completely different conclusion than you do without the aid of religion. That's why you can't rely on emotional or intuition-based morality. The same situation can cause different emotions in different people.
When you're born, both your conscious and subconscious minds are blank slates. When you choose values and accept premises, those go into your subconscious since your conscious can't hold everything you know at once.
Emotions are the result of lightning-quick value-judgments performed by your subconscious mind. The subconscious is like a computer that your conscious programs, and your emotions are a constant printout.
Because of this, your emotional reactions to various situations depend on the values you've accepted and the premises you hold.
When you and someone else agree that it is wrong to arrest a gay man for kissing someone, based on your emotional reactions, it's because you both share western values such as individual rights and the separation between church and state. This allows you both to -feel- that the arrest is immoral. But someone who deeply disvalues homosexuality or deeply values a religion that is intolerant to homosexuality will -feel- -instantly- that the act of two men kissing is vile and the arrest is just and righteous, or at least preferable to allowing the men to kiss any longer.
THIS is why morality has to be based on facts. Why it must be grounded in reality. A person's wrong premises can easily make them -feel- that an evil act is righteous. Morality must be objectively defined and validated in order to stand up to peoples' whims.
Instead of trusting morality to a person's feelings and intuitions, you should examine the nature of reality and of human beings and determine, based on the way we are, what we should do.
I already linked this in another comment, but I'll link it here too. It's an essay Ayn Rand wrote that does just that. It examines the facts that give rise to man's need of a moral code, and then justifies, based on reality and man's nature, the proper moral code for man to practice. (Rational Egoism.)
http://www.aynrand.org/site/PageServer?pagename=ari_ayn_rand...
If you don't agree with this essay, at least you can take from it an example of how to justify a moral code firmly grounded in reality, instead of in someone's -feelings- of right and wrong. Even if such feelings did default to a correct moral code, they would still be unreliable due to how easily they can be overridden.
Having an objectively defined moral code will not only allow you to be -certain- that you are doing the right thing, but you'll have intellectual ammo to back up your code when it is attacked. "I feel this is right" is insufficient to defend any moral code, even if it is the right moral code.