Wavemother's Robe from Baldur's Gate 3
base prompt: ((color)) wavemother_robe, baldurs_gate3, ((color)) dress, side slit, belly chain, cleavage, center opening, front/back/side view
recommended: plunging neckline, long legs, slender posture, hourglass figure
You can adjust robe color by changing ((color)) wavemother_robe and ((color)) dress in positive prompt to the one you prefer.
Tested on 0.8-1.0 with most popular Pony checkpoints.