Any same-sex behavior that could be classified as sexual would be considered sinful. While hugging and even a kiss maybe not be sexual, per se, as they are common forms of greetings, for someone who has a same-sex attraction, they can be. Certainly kissing implies something beyond a greeting, and has a sexual connotation. (I'm interpreting that as something like making out.)
Human sexuality is a gift from God primarily for the context of family; to create families. Sexual intercourse is designed precisely for this purpose, and the joyful pleasure it brings is positive reinforcement that God made it wonderful and wants it to happen. That being said, the children who come forth from this joining of flesh are meant to have parents who will be there solidly for them. For that God created a context, which consists of the mother and father that begot the very children. That is why marriage is meant to be a rock solid bond and to keep families together.
Sadly, we see God's plan less and less in our culture, and there is even a drive to abolish the nuclear family, for example, just read the platform for current activist movements in our country.
So, when it comes to same sex attraction, if it is unable to be redirected toward its natural purpose, (with the opposite sex toward procreative potential), that person is called to live out their life in a chaste manner as a single person. One of my close friends fits this category, is a happy Catholic, and he has a pretty awesome life. It is often difficult to surrender to God's will for your life, but when you do, you find incredible joy and peace. Having same sex attraction doesn't mean forsaking relationships, good friends and intimacy. It means you provide a new context for those things and surrender your sexual impulses to God who will use this sacrifice to bless many others who carry even greater crosses. It is a true path to sanctity and sainthood, which is our common goal.
Therefore, don't play around with the question, How far can I go without getting into sin? Do you know how many girls have gotten pregnant by asking, How far can we go without going all the way?
- Would you get in the car and start it up without driving anywhere?
Our bodies respond to sexual impulses with a surge of hormones that keep pushing us forward. That is the nature of the sexual appetite. If you know that something is going to trigger that sequence then you must avoid it.
I would suggest looking into the group Courage for much more support on these matters, for you should know that you are not alone. I offer many of my prayers and sacrifices for same sex attracted folks so that their burden would not seem so overwhelming. I know the challenge of putting unchaste thoughts, behavior and attraction away, but with God's help I have done well; but I often call upon His help when I feel weak and He strengthens me — and then I offer those sober struggles for those even weaker than me, and I know that God is making us all stronger.
I'll be praying for you too. Know that God loves you and He would never ask you to carry something that He wouldn't help you with.