what do I do with the balls lol?

Ri

i've been with my bf for almost 4 years now but god damnit i still have no idea how to "play" with my man's balls lol. i like whenbi give him head I'll suck on them, but like what else can i do with them lol i rub them a bit but i have no clue if it feels good, or if he feels nothing. I've asked my bf and he's just like, "just cradle them" 🤣 please help tell me