Rob Gronkowski -- SPIKES THE ROSES ... In Wild Hollywood Club Night

Gronk gets bouquet of roses ... Gronk SPIKE BOUQUET OF ROSES!!!!!!

New England Patriots tight end Rob Gronkowski brought the party train out west Monday night ... hitting up the Hollywood nightclub scene with some pals -- and, of course, things got crazy.

TMZ Sports shot footage of Gronk leaving DBA nightclub -- with a giant rip in the back of his pants -- when he was approached by the infamous "rose lady."

What happened next was legendary ...

Gronk got into town earlier in the day and was kicking it by his hotel pool in the sunny 77 degree weather.

#jealous?