So erm basically, I've loved this boy for ages. Not a stupid love but one where there generally hasn't been a day where I haven't thought about him (3 years nearly) I get butterflies when we speak, I light up inside when he pops up not to mention the thought of him makes me happy. Were in the same circle of friends, no one knows about my situaiton as I don't trust many people. We had a little thing a while ago but nothing more. THEN, because of my actions, my best friend got talking to him, he fell in love with her, she did eventually... resulting them getting together for 6 months. Yes I was devastated. They been apart for about 3 weeks, he hates her. Anyway, the problem is I was with him this night, we laid there and cuddled it was everything I dreamed of. For a bit of entertainment, we all played truth or dare, I was dared to snog him so I did. No one knew for a week, as we said it would all remain a secret, his ex/my 'bestfriend' who's always had the better of me, found out and now hates me... what should I do I'm completely confused?

What does snogging mean and how did she find out?
There is nothing you can do unless you want to be honest with her and tell her you have liked him all along.
How old are you?

Snoging is a term of kissing in England,Hate is a very powerful word it's like me saying 'OW I hate prickels" you can't hate your best friend and if she were your best friend she would respect your decision.My best freiend and I had the same Problem,she dated the guy I previously dated sure I felt jelous and sour but over time I realised friendship is more powerful then boys.Talk to her and sort out your prob like young ladies (no yelling or name calling),Just you and her bonding

It was a 10 second kiss really,she found out when him and her were arguing- someone told her then that he got one over her as a joke. She tells me that's its not the fact it was her ex but the fact I'm supposed to be her best friend? This doesn't really make sense to me, I feel like telling her how it feels to have them become an item. Was I really out of order, what do I do now?

You do nothing.
I'm assuming you guys are pretty young. She will cool off, this will blow over. You did your apologies, now leave it alone.
I find it comical when girls get mad at the girl and not the boy. He had a part in this too. She is just mad that he went to you.

Thank you for your help, but as a 2nd opinion- do you think I was out of order by it?

I think it is pretty tacky to mess with your best friends ex, especially if you guys run around with the same friends, but what is done is done.

It was a game and you two kissed so on the surface it was not a big deal. What makes it a big deal is you have feelings for him. Were you two alone or were there other people? That changes to story too.

We (in total 5 people) were all staying in a tent that night, as part of a time waster- we played truth or dare. The thing that annoyed me is that, my 'friend' at the time said 'just do it, its only a bit of fun' everyone else seemed keen to see it happen however when everyone's out talking about me and how low I was, none of those people are anywhere to be seen

Teenage games. She'll get over it.