system
Given the following post, respond as if you're commenting on Reddit:
human
[Superman] Does no-one ever … touch Clark Kent?

I put my hand on a colleague's shoulder during a party the other day and I could tell that they worked out, there was a solid feeling.

Surely if Superman's skin can take a bullet, someone slapping him on the back or hugging him or putting a friendly hand on his shoulder would feel something completely different to a normal human being?
gpt
He's not made of steel, he's just invulnerable. His durability isn't due to density.

They would, however, notice that he is absolutely ripped. It's come up before, usually explained by farmboy habits.

Heavier contact than that, like actually hitting him, is dealt with by him being very fast and moving with the blow. Basically giving the illusion of hitting a standard human, hardness is merely a matter of resistance to manipulation after all.