Here's how I imagine sex on salvia. As I mount my partner and exhale the salvia smoke, I suddenly become aware of how the vagina of my lady friend is currently, rapidly expanding into a giant unzipped hole right in front of my eyes. Then I feel my body get squeezed into a little ball, and slowly, I fall into the abyss of her giant zipper vagina. Then, suddenly my consciousness slams back into me moments later, and I start to laugh uncontrollably. I don't think that sounds like much fun...... actually, on second thought, it sounds like an absolute blast.
And this is a bit off topic, but it relates to salvia and I feel like sharing. One of the absolute funniest things my friend ever said to me happened after we smoked salvia one time. We were at college at the time, and we regularly used to smoke out of my bong in my car in the big dorm parking lot. On this occasion we happened to have salvia. Both of us were experienced users at this time, but about 30 seconds after my friend took his second bong rip of salvia, he opened the door and stepped outside. Already falling into my own salvia world, I suddenly became startled when the car started to rattle. And then i heard them: distinct, clear footsteps, on the ceiling of the car above me. I then saw the legs of my friend through the windshield, as he continued walking forward onto the hood of the car, and then back onto the cement. Immediately after doing this he opened the door to the car and got back inside. I looked at him, awestruck, dumbfounded, out of my mind, and loudly asked him, "What the fuck did you just do?!" He looked at me as casually as possible and as deadly serious as possible and replied, "What, dude? People walk on their cars all the time."