Well, what makes this predicament so much worse for the poor lunar mare is certainly the ballgag, secured in place with a snug head harness. Apart from it being absolutely huge, forcefully stretching her aching jaws, it also makes breathing possible through her nose only. With every breath, she takes in her sister's strong scent, a leathery, slightly sour and pretty feminime pedal aroma. Shutting her eyes only leaves room for intrusive, sensational fantasizing. Keeping them open however exposes her to visual stimulation too, always remindig her the origin of the allurng odor.
With all that mental struggle, she can almost forget about her own naked and exposed, feets, tied together painfully tight, ankles pressing harshly on each other. Or how hard her hair is being pulled from the ropes, putting constant pressure on her arched back. She knows she's already way too aroused from the whole situation and there are still plenty of hours left for the sun to set…
At least the carpet feels soft under her squished breasts!
Tormenting Luna in elaborate bondage scenarios is such a sweet joy uwu. Had a really good time drawing and writing this. Kinda related to this.