Several have suggested that you should decline to attend. I agree, this is the best advice. When I was contacted by elders in regards to Christmas lights I put up after being away for 2 years, I told them that I would be happy to meet with them, but since I was no longer one of Jehovah's Witnesses and in fact an atheist I did not view myself as under their religious authority. And since I viewed the disfellowshipping announcement as a form of slander, I would require any meeting be recorded and that I have legal counsel present.
The elders didn't take me up on the offer. In fact when they did act months later using the one policy they had (dissociation by action) they hid from me, not returning calls or answering the phone. Only after I called them from work and assured the elder he wasn't being recorded did he finally confess that they had made the announcement against my wishes, but only after first lying and saying "he wasn't sure where the rumors had started that I was DF'd"
Now, here is the rub... the elder involved was generally a kind older man, who I had worked along side as a fellow elder. His behavior was shocking to me. But it reminded me of the burden these men labor under. They are not in a position to absorb anything you might say.
For example, you say, one of your friends was DF'd for...
>>the other for french-kissing a girl at a party.<<
Should it ever be normal or acceptable for older uninvolved men to ask questions of such a personal nature? How a couple might choose to show affection and engage in foreplay that may lead to sex, is entirely a matter between the adult consenting couple! Alas, sad to say, when I was an elder I had such conversations. Now, frankly, I'm embarrassed. The moral transgression is not with a young couple doing what is natural to humans and indeed the very reason why we all exist... the moral transgression is that a religion sees no boundaries and without training or insight or consideration of consequences injects itself into such personal matters.
Then there is this...
>>They then told me how i was spotted
with two disfellowshipped in another town over 130 km away.<<
What sort of organization does things like this? What this is showing a insecurity and a hyper concern over loyalty. Totalitarian government regimes spend a lot of time on such things too. Getting their citizens to spy on one another all under the guise of being loyal.
In the end, it is up to you, but I would advise that you not attend. I'd echo Cofty's thoughts. If you have said "yes," I would now say, "On second thought, I have decided not to attend" and leave it at that. Or if you haven't responded, "I have decided not to attend." If they ask more, just say, "I don't want to discuss it." If they say you'll be DF'd, just repeat "I don't want to discuss it."
That way, you've made yourself clear and if they take action, that is on them.