When I think of spooky sex, I often find it interchangeable with taboo sex.
Why? Because Halloween is the only time of the year when people celebrate thinking outside the box in terms of their identity without being judged. You can be whatever you want to be and dress however you want to dress without being looked down upon because everyone else is tapping into a different reality for the night...and sometimes the whole entire weekend depending on how hard your school parties for Halloween.
So with that said, if everyone is embracing a different realm of their identity then why not do so sexually as well? A few specific things immediately come to mind when considering taboo sex.
Sex in public
I've had sex in public a few times, but considering how risky it is, I wish I would have done that at a more convenient time like Halloween. Halloween is filled with all sorts of gatherings and parties, so having sex in public can be a thrilling experience depending on your location. You could find a room a party, lock the door, and carry on. You could also find the opportune time where you know everyone will be out and find a location you know the chances of getting caught will decrease such as having sex on your balcony while you know most people are going to be a frat party or stopping by the library on campus for a quickie before the Halloween shenanigans.
Besides, how likely is it that more people will be in the library that night rather than a club or party unless they have an exam the next day?
Sex with others in the room
Some people may view having sex with others in the room as disrespectful, but I'm not talking about the days where we've all had hookups in our rooms freshman year while our roommate was sleeping. I mean actually having sex in the room while people are actively present just to see if you can pull it off. I've only accomplished this once when one of my ex boyfriends and I had sex in his living room as people were gradually coming in from outside of the balcony. Because we covered up with a blanket, it looked like we were just cuddling and spooning, but that situation could have easily gone south. If it had happened on Halloween we may have found that it could have been easier to be sneaky about it.
For example, a lot of costumes for girls are basically onesies so the place where a girl would button up her onesie can allow for easy access to the goods and then she can make a trouble free attempt to sit on her man and grind subtly. Then when things start to heat up to the point both of you are about to finish soon, she can discreetly button up her onesie, he can zip up his pants and then both of you can take things to the bedroom to avoid an even messier cleanup.
The closest thing I've come to experiencing a threesome was at a kickback when one of my friends and I were dared to simultaneously make out with a guy who lived in the same dorm as us. However, the only time I'd actually be open to having a threesome is during Halloween. For starters, most people will probably be more willing to explore and make their night more interesting. Also, you'll come in contact with a bunch of people you'll most likely never see again. This is perfect if you want to include another person with your partner for a hookup because it'll eliminate how awkward it may be if the third party is a friend.