Neither of them are sexy 7 year olds. The sexiest 7 year old is the one that's cute in a 100% non-performative way. Cuteness is immaturity + a will to mature. Without the will to improve you just have a shitty brat festering in shallow forced aesthetics. The only way there can be any kind of authenticity is if you are willing to let the cuteness be destroyed. The best cuteness can only ever arise from respecting and taking something cute seriously. The most arousing child is the one that just said their first word, that just took their first steps, that just learned to see through your trolling them, that just learned their ABCs... How can you stand to jack off to a kid who just performs a poor facsimile cuteness over and over as a way to draw people's attention?