I was pretty surprised to see neither "testicle sucking" nor "sucking testicles" ( as the boorus would tag it ) really recognized by Illustrious, so I've created this to remedy it. "licking testicle" sort of works, but it isn't the same idea. If it does somehow recognize it under another term and I'm just dumb, that's entirely possible, too.
Some times it will get confused and revert to regular fellatio, but prompting can guide it along. Adding fellatio, blowjob to the negative can help.