How to set up a 'real' live gay sex venue: Exploring ideas

Is there any way to go about setting up a CMNM (or, for that matter, just plain NM) scenario with guys you know--without freaking them out? I know a guy or two I might like to have such a scenario with (maybe with some touching or contact but not necessarily any sex), but I don't know how to actually go about approaching the issue in such a way that I don't inadvertently transgress any of their personal boundaries and/or make them uncomfortable.
Like, my roommate, for example. I'd like to be naked around him or with him, but I can't very well say "Hey, dude, can we hang out naked sometime?" That might really weird him out. But, if there were the potential for him to be open to it, it would be something I'd want to do. But, I don't know how to approach the issue at all. I don't how to approach it in a way that I could find out if he'd be open to it without simultaneously risking offending him or making him uncomfortable. Any thoughts?
Here are some ways I can suggest:
Come up with natural, unforced occasions when you can get naked in his presence or at least allow him to see you nude. Changing for bed or getting into the shower.
You may have to 'set up' some of these -- if it's something that's not been any part of your style of living. - Such a 'set-up' might be forgetting something like a towel or wash cloth when you're in the shower, or running out of soap or shampoo and having to come out to get some (or one that you just bought but 'forget' to bring with you. - Use your cellphone to ring (set up the alarm to ring) while you're in the tube and you rush out of the bathroom naked "not knowing he was there" story to grab your phone.
Let him catch you naked a few times innocently. If you are now walking through the house/apartment nude, then it might seem strange to just start doing so. So you first have to get him used to seeing you in various states of undress. Start my coming out with no shirt or lounging around only in your boxes or athletic shorts.
Later try to set up more 'naked' situations where he catches you naturally.

This might be his knocking on your bedroom door (to get something you borrowed or that you share - cordless phone, vacuum cleaner, etc). (if you have separate bedrooms) and you're nude doing something like trying to untie some knotted shoelaces (and you may have the stereo/TV on) or headphones on (so you can't him knock).
Other ideas:
1) Start freeballing - that way you'll already be half naked. Your roommate will get used to seeing your cock, balls and butt if you undress where he can see.
2) If he's too uptight, he'll keep looking away or even ask you to dress in your own room. They will give you clues about how to proceed.
3) If this avoidance behavior persists, especially if he mentions it or draws some attention to it (like leaving the room), you could confront him about his being too uptight or too restrictive on your own personal freedom.
4) If he jokes about it, then you could also joke back with him.. 'Try it out, you might like it'. Just be upfront (and clever).. " seeing me naked doesn't bother you, does it?" How would he answer that but say 'No, not at all."

5) Start a new activity that involves him and you -- and the possibility of nudity - swimming for fitness, gym, fitness club, yoga, weekend sports, jogging, weekend trips or day time outing to the lake, beach, etc.
6) Always sleep in the nude so it won't be strange for you to be naked in and around your bedroom, also when you and he get to do some overnight trips or camping, etc.
7) Get a friend who is a nudist and whom you visit with your roommate. The friend can invite you and your friend to get naked (whether he's gay or straight or with a woman) the 'pressure' of your friend's request might help him to break down the barriers so he'll actually get nude too. At least, you can accept your nudist friend's invitation - so you'll be naked in front of your roomie.

You could do something so innocent as:
A) meet in the in-house bar/restaurant for drinks or snack,
B) come visit him in his dorm room  or apartment,  and then get around to getting somebody naked - either one of our 'cmnm' group or maybe some of the other guys staying in the room (is that unethical?) -- maybe? But it could be a whole lot of fun.
3) Hold a party in the room and play strip poker (or an easier kind of game where the loser has to remove a piece clothing until some (or all are naked).
4) More clever would be for several of your group staying in the same or nearby rooms and then pretending not to know each other.. .. so we can get some going like one guy jerking off in his bunk, and then another guy (our member joining in). It would get some of the other guys (not our group) horny and they would join in the fun... Maybe a little farfetched... but you never know until you try. Outside the hostel... it's very large and could be very crowded

5) Try doing some naked dares and having buddies to watch out / bring your clothes to a rendezvous point, or take photos, etc. ...
6) You might try going to a bar/club where nudity is either allowed or required

7) Perhaps some one would be willing to host a small group in his apartment, office lounge after hours..etc, for some naked fun.
8) Another idea is to have pre-selected roles for a type of simulation - visit to a doctor's for an exam. One guys in the patient, another two play the role of physician and or specialist, there could be a male nurse who gives sponge baths.  It's up to your imagination.
 
Am I losing you here? There are other roles that come to mind.. but it takes a bit of energy, a passion for realism but with a big dose of fantasy, and a suitable place where that could happen.
I hope you're able to get off with a guy if one of these tactics works.