Justin Bieber is Pissed!!!

We know Justin Bieber's pissed at The Weeknd ... but who knew it was literal?

Biebs was cruisin' along Wednesday in WeHo in $400 sweats that will now resell on eBay for either a lot more or a lot less.

His aim on the basketball court clearly doesn't translate.

Even Justin thinks the pic is a wicked pissah ...