The antonym for curling up is stretching out. Curling up is characterized by bending one's body into a compact, coiled position while stretching out involves extending the body into a larger, more expansive position. While curling up may express feelings of comfort or protection, stretching out indicates a desire for openness or freedom. In contrast to the comforting, inward focus of curling up, stretching out involves an outward focus on the environment and one's surroundings. So, if you want to break out of your comfort zone and enjoy a more expansive and free experience, try stretching out instead of curling up.