Which's the best undie for him?

Still at Kabane-kun. XD I really like him. I plan to draw him 1 more set after this and we will move on. LOL But who know I may draw him more after that. LOL. Ok I plan to use the comments as you choose on our next set of him. So.... :D Which undie is the best for him? xD

Fantia: https://fantia.jp/posts/593783
Hiccears : https://www.hiccears.com/gallery.php?gid=17259