Caius doesn't really lie as it makes him feel guilty and he hates it if others are lying to him - but he may not always tell what's really on his mind, only gives half truths or tries to avoid the topic entirely. With his poker face he can be convincing. The person he lies the most to is himself.
Lots of green plants and flowers to add the comforting scent and feeling of the woods. As much blankets as he can find if he sleeps there and some kind of light source (candles, lamps, string lights), preferably a place with a window to the night sky, he can't sleep surrounded in total darkness.
I play on console so I only do vanilla gpose, but I love it! โจ๏ธ It's fun to learn and see what you can do with it
Remembering little things they told, wanting to spend time with them and actively seeking their company. Little touches - encouraging pats on shoulder, holding hands, standing so close elbows touch, hugs. Words are difficult for him, so it's mostly with actions.