This AWFUL, AWFUL Monegasque girl I have known for ~10 years. I have only spent time with her in 2-3 hours chunks. A group dinner, drinks, out at a bar, etc...and she was always pleasant enough in those settings, if a bit neurotic. The last few years, I think her mental health has been going downhill.
Anyway, I planned a multi-week group trip with some close friends around new years to Goa, Zanzibar, Hong Kong and the Philippines. This girl invited herself along on the ENTIRE trip, and I figured, what the heck, why not.
By the time we finished connecting from Mumbai to Goa, the first stop, everyone else in the group hated her. She treated them all like garbage, almost as if they were her servants. On top of that, she showed up on the trip with no working cell phone, no debit card, no credit card and roughly 1,000 euro in cash.
On the way from Goa to Dar Es Salaam, she misconnected in Doha, because she accidentally booked DOH-DAR the day AFTER the rest of us were scheduled to fly. We had ~4 hours in Doha airport, and she didn't think to mention this until we were boarding, then became incredulous when we all refused to skip the flight in order to help her figure it out.
She (unfortunately) soldiered on and made it to Zanzibar the next day. She showed up with no reservation and said she had to stay in my room and mentioned she spent all 1,000 of the euros she had on the hotel she needed for one night in Doha and asked us to cover her, saying she'd pay us back at the end of the trip.
As you can imagine, everyone began just outright ditching her and hoping she'd miss a flight somewhere along the way and get the picture and give up and go home...that never happened. She stayed for THE ENTIRE trip and managed to rub everyone she met on every continent the wrong way. As an added bonus, when the trip concluded, she decided since we had tried to avoid her, that absolved her of the responsibility of paying us back.
We've since instituted a system that no new people can come on trips unless 3/4 of the group votes yes, to avoid "Nathalie situations."