Pauly D's Done with Aubrey O'Day, But She Doesn't Know It

Pauly D's 9-month relationship with Aubrey O'Day is over and he's already trying to erase her from memory ... TMZ has learned.

According to our sources the DJ and the singer ended things over the weekend -- just a few days after she left to shoot "Celebrity Big Brother." The exes actually got together while shooting another reality show -- "Famously Single" -- last Fall.

It's unclear what set off this split. They'd broken up for a few days back in May, but this time Pauly's scrubbed all images of her from his social media ... and there were a lot of them.

Here's the thing ... if Aubrey's sequestered in the 'BB' house, we're guessing she has no clue she's single.

Last week when she left for 'BB' she posted a pic of Pauly with her 2 dogs, saying ... "My dearest hubby, I will miss you so much. You are my best friend, my love, my person, my soulmate!"

Whatever.