When talking with youth, I commonly get asked the question in the context of dating relationships: "How far is too far?"  Not all dare to ask the question, but most are thinking it.  So let me address this here.

First of all, this really isn't the proper question to be asking.  I remember when I went to the Grand Canyon when I was five years old.  We went as a family in the station wagon with my brother and sisters  on a trip to Disneyland and made many stops on the way.  When we arrived at the Grand Canyon, my dad was pulling up at a spot to stop where you had a great view of the grandiose site that reflects God's greatness.  But my dad decided to have some fun with us, and kept inching up to the edge (if I remember, there was no guard rail - at least I couldn't see one).  The closer he got to the edge, the more all of us kids would holler for him to STOP!  None of us wanted to find out how close we could get before the car would fall.  The natural response is to want to make sure you don't get too close - to stay on solid ground far from "the point of no return."  Well, this should be our attitude when facing this question - even more so.  In the long run, spiritual death is a worse tragedy than mortal death.  (Read Pure Love for more on this.)

With this said, let me go ahead and address the question.  Many think that as long as a couple does not "go all the way" then there is no sin (or at least mortal sin).  But this is not the case.  Any form of intentional sexual arousal outside the context of marriage is seriously wrong (and not all inside of marriage is okay!).  This would include self-arousal, petting, intimate kissing, pornography, intentional impure thoughts, etc.

You may be saying "Wow!  Is this guy from Mars?! Nobody thinks like that anymore!"  No, I'm from Earth and my viewpoint would have been considered common knowledge by all Christians and Jews for many centuries.  It's still the clear teaching of the Church, but the problem now is the degree at which this teaching is confused, hidden, and attacked in our modern time (including when I was a teenager!).  We don't really know what love is and what sex is about in our modern culture.  (If you doubt me, look at the high rate of divorce, abortion, sexual promiscuity, STDs, etc. and all the destruction and hurt that results from this in our society.)  The Church is faithful to the teachings of Christ and Jesus knows and wants only what is best for us!  We need to trust in this and act upon it.

So, yes, you'll be swimming against the tide, but we as Christians are called to be "counter-cultural".  Jesus tells us clearly: Enter by the narrow gate; for the gate is wide and the way is easy, that leads to destruction, and those who enter by it are many (Mt 7:13).  You'll need a lot of prayers and support from those who are committed to following Christ and His teaching on this matter.  But we need to realize that if Jesus wants this for us, it's the absolute BEST for us.  And I can testify to this.  In my relationships where I practiced "pure love", it was VERY EXCITING (and a side note to the guys - the girls (at least the good girls) really love it!).  The "further you go" the further you have to go to get the same thrill.  So drawing the line back at minimal physical intimacy gives a whole new meaning to the taking of the other's hand or the giving a kiss on the forehead as you say "good night" (on a special occasion when your relationship "moves to the next level").  The "fireworks" can go off with a mere hug!  (A brief one, of course ;-)

But the best part of this "purity in dating" is how it makes the process of discernment easier (i.e. Is this really the right one for me?).  And if this one isn't the right one, the "breaking up" is much easier also.  Trying or having to end a relationship where you have been too intimate sexually causes great pain and leaves deep and even permanent scars on one's heart.  On the other hand, I can honestly look back on my relationships where I "played by the rules" with great joy, respect and deep Christian love with the girls I dated.

One thing to keep in mind - don't think you're Superman/Superwoman.  The sexual desire is very strong and fed by movies, conversations of others, ads, etc.  Keep away from situations where you could easily be "pushed over the edge" - keep your conversations pure, double-date, make your one-on-one time (which can be very romantic without being physical) in a public or semi-public place (like a park or nice place on campus where others are present), avoid movies and television shows that promote impurity, etc.  Also, dressing modestly is a big help.  And the best defense is a good offense - pray, go to confession weekly or monthly, go to Mass daily if possible, spend time in adoration before the Blessed Sacrament, read Sacred Scriptures frequently.

Be creative in ways to prevent "falling in to temptation" - be practical and plan ahead when you have your wits instead of relying on your reason and will when your emotions are taking over.  I know of this one girl who, when she went out with her boyfriend, would wear undergarments that she "wouldn't be caught dead in."  If the will-power to do good and avoid evil were too weaken, she always could rely on her strong desire not to be embarrassed!  Hey, you can't be too safe in this area.  Be creative!

Other strong motivators to overcome the temptation are the obvious negative consequences of sexual relationships outside of marriage: unwanted pregnancy, sexually transmitted diseases (and, NO, condoms are not the answer), and, yes, eternal damnation in Hell (which is the result of dying with any unforgiven mortal sin).  Read more about these realities and contemplate them to give you extra strength to say NO not only to the sinful act, but even to allowing yourself to fall into the "near occasion of sin."  (It's a lot easier to stop a slow train on a level surface than one going full steam down a hill!)

If you find yourself in a relationship where you are "physical", there is NO excuse not to go back to a pure dating relationship.  Go to confession and make a commitment to one another to this more loving, pure form of relating.  In this case, some of the practical advice above for "avoiding the near occasion of sin" will be of utmost importance to get the "train back on the tracks" and keeping it there.

Commit to "playing by the rules" and watch how God blesses you and your relationship!