If I clench my glutes together very hard, it causes a really pleasurable sensation. It's too tight and awkward a contraction to sustain for long, and clenching and unclenching doesn't really have a useful effect. But god damn that moment when it works is good. It's weirdly like being penetrated, a very deep feeling somewhere I definitely can't reach with my fingers.
Can anyone else do this? (For me it seems to work best if I'm standing with my legs about shoulder width apart, it doesn't work as well when I'm sitting in a chair.) Does anyone know what's going on anatomically?