What is this challenge? (2019) (Patreon)

Maxime: Oh Thomas!
Thomas: Hi Max!
Maxime: * I look at the pectorals of Thomas surprised * Er ... Do you do with your goblet on your chest?
Thomas: Oh that! This is a boba challenge that is all the rage on the internet, trying to hold his cup with nothing that is pectoral, what do you think? *smiling*
Maxime: * I'm puzzled * Hum, you know the challenges of this kind is not my thing, then what's the challenge?
Thomas: Well it's obvious my friend bear, for fun! *He is laughing*
Maxime: * I sigh * I do not see what's fun in there.
Thomas: Because you did not try, maybe you would understand.
Maxime: Yeah! It's possible.

FurAffinity: https://www.furaffinity.net/view/32106246/