No it wouldn't, because Sunset Shimmer is a unicorn and Spike is a dragon.

They're still who they are on the inside and they both came from the pony universe, so there's nothing wrong with it.



The only EG shipping that can be categorized as "bestiality" would be shipping Flash Sentry with either Twilight or Sunset.

Because u'd be shipping a human (Flash) with a pony turned into a human (Sunset and Twilight) that's bestiality.