2 Cups and a Guy - Moxibustion

I had this done to me last week at the Acupuncture school. It is called Cupping & similar to Moxibustion Therapy. I'm not sure which or what was done to me since I was lying on my stomach. But basically a thin layer of baby oil was rubbed on my back. Two bulb looking glass shapes (the cups) were like lit with a lighter to the inside of the bulb which created a vacuum which made the "Cups" stick to my back. The intern doc just shifted the cups around my back leaving them in spots for a few seconds while still staying stuck to me. It didn't hurt nor was it hot. It was a weird feeling though and my skin felt pinched if the cup stayed in one place too long. I guess the purpose is to stimulate certain Acupressure points. I felt my back loosened up though.