GPIO pin shocked with 5v

this is kinda stupid question, but what will happen if the digital GPIO pin on a specific socket on the fez spider will be signaled with 5v and not 3.3v like i saw in a module creating guide?

will it work? fry the circuit? just wont work? fry something else?

Depends on MCU. The datasheet usually specifies tolerance.

Most GHI SoM’s are 5V tolerant (G120 for example is). This means it will not harm the CPU, but the current is a bit higher.
Look in the GHI Brochure or the CPU Datasheet to be sure.