The Equestria Girls Snips lost a bet with his friend Snails which gave him the choice of punishment like dressing up as a clown for a day or wearing a dress and makeup for the day. He chose to dress up like a girl and to his dismay, he regrets it...but secretly likes it.
I've been wanting to draw Snips and Snails wearing feminine clothing mainly because they look girly to begin with. When they both transformed into demons alongside Sunset Shimmer they also looked girly-ish even then.
