Dru Hill -- We're Still Singing ... To Feed Our Kids

Real talk last week after a Dru Hill show in DC -- the 90s R&B group said they're still kickin' for one reason and one reason only ... to put food on the table for their families.

The singers were sitting for an interview Wednesday with AOSTL media group reporter Donna Jones -- she tried to ask how the guys deal with the ups and downs of a music career ... and Sisqo tried to give a thoughtful response ... but his pal Nokio cut him off.

We won't ruin it ... but Nokio doesn't mince words.