EXCLUSIVE

Justin Bieber has become twice the man he was last month. First, making a pilgrimage to the Great Wall of China (it's a whole Chinese thing), and then, last night, touching a stripper's ass.

Biebs not only went to a Texas strip club, it's a particularly raunchy one where girls do things that leave marks.

Biebs hit up VLive ... enjoying time with his shirt off and pants down. Here's the highlight ... one of the strippers tweeted afterwards, "He touched my ass I almost fainted." She also had this introspective observation -- "I've danced for a lot of celebrities and they normally don't phase me but Justin had me in shock!"