Well, is it the character's intention to "out" other superhumans? If he does, that would create a source of conflict, wouldn't it? The idea of powers needing to be "secret" only harbors suponse when there's a chance of exposure. 

It should also be recognized that players are already in the know of who's super and who isn't, so there's no real surprise factor if someone's character is "discovered." 

I, for one, (as someone looking to apply) am entirely comfortable with another character being able to "sense" the presence of superpowers.