Bring 1 cup of granulated sugar and 1 cup of water to boil over medium high heat, stirring until sugar is fully dissolved. Add one cup of washed, de-stemmed edible honeysuckle blossoms and 1/8 teaspoon of lemon juice and remove pot from heat. Cover and let steep for approximately 30 minutes until room temperature. Strain liquid through a fine mesh strainer in to an airtight container and refrigerate.
In a shaker with ice, combine honeysuckle syrup, gin, and grapefruit juice. Shake until chilled and strain into a champagne flute or coupe. Top off with sparkling wine and garnish with fresh honeysuckle blossoms.