I have been a long-time reader of this board, and created this account to post my question. This will be my first year to attend BM and I am extremely excited! I would like to ask a question though about my camping arrangement and seek advice - of any sort - be it snarky, critical, lighthearted or whatever.

My ex (has been to 6 Burning Mans) invited me to attend this year and join his theme camp (approx 100 total in the camp). We broke up about a year ago and talk a few times a month and generally have a civilized friendship. He invited me as a friend, not with any expectations of sex (we talked about this to be clear). So, he got me an early-entry pass and I have been connecting a lot with other camp members and am very excited about being part of the camp. Because he doesn't make a lot of money and I could spare it, I offered to pay his camp dues as a sort of 'thank you' for bringing me into the camp and introducing me to his friends. He mentioned that he would be very appreciative if he could sleep in the RV (not 'with me', but in a separate bed) and I agreed because at this point it's just me in there and I have extra room. We talked about some ground rules for the RV (only using for sleeping/shelter for dust storms, etc, being respectful about bring other people into the RV for shelter or to offer a bed) and I had a really good feeling about it.
Now, here's the part that I'm feeling awkward and uncomfortable about: he told me a few days ago that he has a girlfriend that made last-minute plans to go too, and he casually mentioned that she, of course, would be staying with him in the RV. I've never met her, and I have zero issues with her presence to get shelter there or even to sleep there. My issue is that I don't think I would feel very comfortable with them having sex in it while I was 2 ft away in my own bed. I have zero interest in hooking up with him (have a few times since our break-up but it was super casual and no-strings-attached... but wouldn't be doing it now that he has a GF), and am happy he has a new GF.. just don't want to inadvertently sign myself up for a situation that might be upsetting or uncomfortable.
When he mentioned adding her to the RV, we discussed a few extra considerations that would need to be made for a third person (place to store her stuff, what she wanted to bring, make sure she was comfortable with the ground rules for the RV we had already setup, etc) and I let him know that I don't think I would feel comfortable with them having sex next to me. His response was a jokingly dismissive, "RELAX! It's Burning Man, everyone is having sex and you won't even notice!" Then, when I reemphasized my concern, his response was, "You'll probably find one of my friends to sleep with anyways, so I don't see the problem" (LOL Are you beginning to see some of the reasons we are no longer a couple...). So, my question is, what might be a good way to handle this situation?
A few other considerations:
-If he isn't in the RV, his plan is to sleep in his truck.
-I wouldn't have sex in the RV if he was in there, either.
-I am already very committed to this theme camp (already have jobs that I have signed up for, paid dues, made friends there) and don't want to leave the camp
-I have every intention of being welcoming and friendly to his GF and am perfectly ok with her being in the RV, offered her a ride & other help, etc
-Suggested that he elect to have sex in the RV anytime of day or night that I'm not in there, but not to intrude on my personal boundaries if I am there.. his response, "No promises! It's Burning Man! It gets pretty crazy!"
-Because I consider him a friend (it's sort of a love/hate thing..) and he got the ball rolling for me to go, I don't want to be mean and ask him to not be in the RV at all (even though there are several other camp-mates who have expressed interest in joining the RV)
-I'm desperately seeking a drama-diffusing solution that we can all be comfortable with
I'm concerned that he might agree not to have sex in front of me, but then might get drunk and forget about the agreement and have sex anyway.
I've done my best to think this over on my own and really could use some advice from someone looking in on this situation. Thank you all and I'm sure I'll come up with a way to make my first experience fun regardless!!! I can't tell if I'm over-thinking it and maybe it's really not something that would bother me.. just don't want to set myself up to unhappy. Thank you for reading all this, and for any suggestions you have!