When Sunburst came to Ponyville to visit Starlight, he always made it a point to visit Trixie. The unicorn was cocky,sure, but he genuinely liked her magic tricks and her shows, they were always so flashy. He often met with her after her shows to go train her to use more creative magic, and to do more advanced spells to make her show better.
 
Soon they started really enjoying each others company and fell in love with each other. Trixie didn’t share many interests with Sunburst, but that never stopped them from hanging out for hours. Eventually after getting married they had a foal, they settled on the name Moonburst.