Biome-dependant biomes

So, I made two biomes; Surface Crimson and Underground Crimson (these are from terraria lol, thats the mod ive been cooking), and where they spawn is as clear as water. However, I want to make it so the Underground Crimson only spawns underneath the Surface Crimson, be it close to it or directly.

Is there any way I can force this to happen? Because changing the temperature range and such is only going to limit how widespread the Underground Crimson is, not force it into spawning alongside the Surface Crimson.