01 - Place the watermelon cubes and strawberries in a blender, ensuring they are clean and ready for processing.
02 - Pour in the lime juice and sweetener if using, adjusting quantities to taste preference.
03 - Blend on high speed until completely smooth, approximately 1-2 minutes. Stop to taste and add more sweetener if desired.
04 - Pour the fruit mixture evenly into popsicle molds, leaving about 1/4 inch space at the top for expansion during freezing.
05 - Insert popsicle sticks and place molds in the freezer. Freeze for at least 4 hours or until completely solid.
06 - To remove popsicles, briefly run the mold under warm water for 10-15 seconds, then gently pull out the sticks. Serve immediately.