Set grill to medium-high heat. Lightly butter the corn and wrap tightly in foil.
Grill corn for 14-16 minutes, turning once halfway through. Remove from grill, carefully unwrap the foil, and set corn aside to cool. When cool enough to handle, cut kernels from cob.
In a medium bowl. combine all remaining ingredients. Add corn kernels and serve immediately.
Notes
If you don't want to grill the corn, you can broil it instead. Cut the kernels from the cob, spray them lightly with cooking oil, and broil them for 5-7 minutes, turning once halfway through.
Recipe by Simple, Sweet & Savory at https://www.simplesweetsavory.com/grilled-sweet-corn-guacamole/