Dredgie

When your dress goes into your butt like a wedgie, its called a "dredgie".

"Look at that's girl's dredgie! How does she not notice that half her dress is stuck between her cheeks?"

dredgy

The act of fingering your clothed girlfriend, until her panties are quite damp, but not enough to get her off. Pull it out, hug her, while grabbing her ass. While she enjoys the hug, slide your hands down her pants and give her a surprise wedgie. The ensuing damp panties up her ass crack will cause the full effect of the dredgy.

My girl was being ornery, so to get back at her, I pinned her against the wall, fingered her until she almost got off, and then acted like I was going to grab her ass before I gave her some dick. Then I put her in her place with a dredgy!