The on-again, off-again couple hit up the picturesque Mulholland Drive in L.A. Wednesday night on Channing's BMW bike for a nice sunset ride. It's unclear if they've been quarantining together but you know it's "safety first" with them ... look at those sturdy helmets. She also has her arms wrapped around him ... you can make the PDA or safety argument here.

Looks like these two crazy kids just can't deal with being split up. Remember, they dated for about a year before calling it quits in December ... only to get back together a month later.

Then, earlier this month, they split up again. The breakup didn't seem acrimonious at all, because just a few weeks after breaking up Jessie J took to Instagram to wish Channing a happy 40th birthday with a series of pics and vids. She also tagged him in that post.

And, just a few days after that post ... we see them riding together. The heart wants what the heart wants, right?