The Church is often accused of being too legalist, even though it is not and that is why we have these questions.
Our very own Karl Keating had a good synopsis of the issue. Here is the link:
How far is too far with a girl? Specifically
Ultimately, the answer will not satisfy us who are seeking absolute boundaries. While there are many absolutes (we’re really not supposed to ‘touch what we don’t have’ because my understanding is that such would be in itself pretty serious), there are elements that no one can completely instruct on.
A lot depends on motivation and what we are thinking. In all likelihood, when we think of something like French kissing, our mind is not filled with pure thoughts.
On the other hand, I think that there is the problem of going too far the other way. My Priest said that things are so bad now, that there is the potential for a reaction in the complete opposite direction akin to Saudi Arabia or a situation where showing ankle is forbidden.
Sometimes we get too caught up on ‘what can I do, what can’t I do’ and lose sight of the why, which is purity and closeness with God. And I accuse myself of this first.
I can personally see passionate kissing possibly being okay given the right circumstances (e.g., engaged, lot of self control, etc.). Similarly, I could see watching a movie together on a couch sitting close being pretty natural and just an expression of companionship.
But… for a lot of us, I think we want to believe ‘oh I will just keep it there.’ Then hands slip. Our flesh starts to kick in. And then we’re all up a gum tree.
We have to do the best we can to avoid sin and that means avoiding the occassion for sin. This means different things for different people.