Dennis blinked for several moments: the urge to laugh at the ridiculousness of the situation warring with compassion for the obvious levels of vulnerability that Seamus was feeling. This was all brushed aside by a certain level of fascination with the scar tissue stretching across and wrapping around Seamus' upper legs. It was a curse scar obviously, but Dennis wasn't entirely sure how it had come to be where it was. He was also deeply certain that asking would probably push Seamus over the edge, thus he forcibly quelled his curiosity.
"Thank you for showing me," he said at last after Seamus was decent again. "I'm sorry that you have a scar. Also the whole undressing thing was a bit weird, but thank you for showing me. I can show you the scar Colin gave me when we were kids if you like? It's my favourite scar because it's so stupid."