Selena Gomez is rubbing it in the faces of all those folks hating on her new romance ... sharing yet another loved-up image with new BF Benny Blanco a week after confirming they're dating.

In the black and white image shared to her IG Stories Tuesday night, the "Only Murders In The Building" star cuddles up to her man ... sporting a big grin as she adoringly grabs onto his arm.

This is just the latest B&W snap Selena has shared with Benny -- who she's apparently been dating for 6 months ... which was right around the time of her 31st birthday.

Indicating they're super serious, she's also posted shots of her "B" ring, and she showed off the sparkler while enjoying a beverage in one cozy snap.

It's been a rollercoaster week for Selena ... who felt the need to defend her relationship from online critics blasting her for "dating down" following romances with Justin Bieber, The Weeknd, Taylor Lautner and Nick Jonas.

Selena handled those comments immediately ... firing back that she's "never dating a f***boy ever again" -- though her response to other criticism was a little more indirect.

When people began slamming SG for going hard with her new romance with BB, but shying away from the Israel-Palestine issue after catching considerable flak ... she replied, "You're right."