Kurt hadn't realized that this man was Dawn's father. Not that it would have changed whether or not he'd tell Marcos about Lorna and her daughter. Their daughter. Marcos had the right to know about Dawn. Whether it came from Kurt or from someone else... he'd have figured it out somehow.
"You'll be okay here. Safe. It's not bad here, really. No one is out, trying to kill mutants or anything." He knew that Marcos was a mutant, because really... who else would have heard of Kurt Wagner and could do what Marcos could do and not be a mutant?