Charles has an odd obsession (and yes it is an obsession no matter how the telepath might protest because Erik knows obsessions when he sees it) with animals, scary animals to be more specific. That is why when Erik came home from a day of training with the kids to see a scary looking panther lying by the door he can't be surprised and neither can Hank nor Alex nor Sean nor Raven (especially Raven because she's known Charles the longest and has survived a grizzly bear, a shark, and an alligator) because Charles had a thing for scary animals and maybe that's why he likes Erik so much.
The human mind is very abstract. The mind is a place of shapes and colors and objects that signifies some specific meaning over the person. It is full of ideas and wants and needs that create a…something that can't really be explained unless you've seen it which is very frustrating for Charles whenever one of the children will ask what their minds look like. But that doesn't stop Charles from trying because he wants some way to classify it because he's a man of order and understanding and how can he teach the children if he doesn't understand his own gift. So he tries to tell Raven that her mind is full of circles and yellows and elegance and comfort, but he can't because even in his own head it doesn't sound right so he tells her that it is hard to explain unless you've seen it which makes her all huffy because she wants to know and hates not knowing and Charles hates not being able to tell her.
Every Sunday afternoon, the makeshift family of mutants takes a break from training to do something family-ish. It is sweet and enduring especially because the children don't really know what a family outing entails unless it's been shown on TV or read in books so most of their ideas tend to be very old fashioned and clichéd and too cute for words as far as Charles is concerned.
That is why this afternoon the family finds themselves having a picnic in a clearing a mile or so away from the main house, but still on the Xavier property. Hank and Raven are discussing something in hushed voices under a tree a few yards away from Charles and Erik who are taking a nice afternoon nap (or at least Charles is as Erik runs his fingers through Charles hair). Alex and Sean are playing tag and giggling like school girls as they do sillier and sillier things until Charles tells them to calm down and stop thinking so loud. And it is all so peaceful as the summer afternoon drags out around them that all none of them wish for it to end.