Justin Bieber Singin' About Sizzurp

4/29/2014 7:42 AM PDT BY TMZ STAFF

Justin Bieber
's so gangsta' these days, he's now droppin' sizzurp similes to describe his interpretation of "love."

The Biebs posted two new songs to SoundCloud -- under the ridiculous name Sir Bizzle -- one of which is an atrocious ballad called "We Were Born for This."  

Biebs has never included sizzurp in his music before ... but threw a reference in his new song: 

but the boys and the girls
they don’t know
what love is like
love is like appreciation
mixed in a double cup of sprite


As TMZ first reported, Bieber has a long connection with sizzurp ... having once been caught on camera in an ATL nightclub holding a double cup

Now, it's clear ... he's not afraid to mix work and play.