Haha... I like it! Pegasuses have their Wing *plumpf* so it makes sense Unicorns have a little Horn *Spurt*! However, I'd think it be more a *sparkle* or *crackle* with this. I can't imagine a discharge of magic making such a "wet" sound. However, while I did have that criticism, its still very funny
Also, what's an Earth Pony do when aroused? Buck? Twitchy Back Leg? Or being very traditional, do they just get a boner?