You should be cautious here.

many people say that they would never engage in sexual activity with a LG, and that doing so would be wrong.

Not wrong exactly, just illegal and could end up causing problems for our young friend.

my question is, is there any exception to that?

None that I am aware of.

if i am 25 and i get to know a girl who is 13, befriend her, hangout and then eventually get to a point where we are making out and cuddling but no sex, in your opinion is that harmful to the girl?

I think it is obvious that the acts themselves would cause no harm at all to the girl. If the girl cared about you, and was attracted to you and wanted to engage in those activities, then there would almost certainly be no harm. Note that I am not talking about penetration of any kind with the girl. I am talking about kissing and sexual touching.

now like i said i'm not asking if its illegal or if its morally wrong but do you think that it would be harmful to the girl?

Again, as long as is the girl is a willing participant and her needs are listen to, then the acts themselves would not cause her harm. Quite the contrary, the girl would likely find the activities very pleasurable.

say they have a friendly relationship for a few months experiment sexually, (kissing,cuddling, second base) then say her families moving away, you say your goodbyes, and keep in touch, and be life long freinds!! i think thats a perfectly good scenario where it would be totally ok....like i said i am very interested to see peoples response...pro or con, if you think i'm wrong please tell me, i'm always trying to sharpen my opinion!

Here is where we differ. First, those activities (short of sexual touching) can still be considered illegal in many countries. Sexual kissing of a minor can even be illegal. Sad, but true.

Second, even if the girl loves you and is willing, it is likely that others will know about your romantic and (partially) sexual relationship with her. It is even more likely that those people will step in and try to end the relationship. They may even get the police involved. All of these things will result in harm for your young friend.

Finally, what if the girl falls very deeply in love with you and wants more? What if she wants to be your girlfriend and make love to you? Would you be able to tell her no? Would you instead end the relationship and break her heart?

Your entire premise is based on the notion that this girl will not become emotionally attached to you. It's likely that if you were to pursue this kind of romantic relationship with a girl of 13 that both of you would fall in love and that would greatly complicate matters.

Never forget that when the human heart is involved, outcomes are almost impossible to predict. This is why we must do our best to avoid romantic or sexual relationships with young girls. The risk of harm that could result from unintended consequences or from society is simply too great.

If we love our little girls, we cannot risk putting them is situations where they could be harmed, even if the harm does not come directly from us.

No, my friend, I am sorry to say that we are just not Lucky enough to have this kind of relationship with a young girl. But that does not mean we cannot have close friendships with girls. I hope you find this helpful.

Laterz.