Justin Bieber and Selena Are Back Again

Just days after coming together ... Justin Bieber  conceded he's still kinda in love with Selena Gomez -- and in a clear sign they're banging again -- J.B. posted this pic online.

In the picture, Justin flashes his signature blank stare and says, "Love the way you look at me" ... while Selena cuddles him from behind with a one arm hug.

As we previously reported ... Selena hadn't been spotted with JB for months until earlier this week.

Every woman learns -- you can't resist the Biebs.