Seulgi commented, "Oh pretty [heart emoji]." Of course, Jisoo reciprocated the Red Velvet member's post with, "I'll take a pic of you wait a sec [emojis]"

After this cute interaction between these gorgeous ladies, fans began clamoring for a "BlackVelvet" collaboration. 

It's not news though that the two groups are pals, noting that Irene and Jennie are close friends and were even spotted hugging each other for long during an awarding ceremony. Also, it's not the first time that Seulgi and Jisoo exchanged comments on the photo-sharing app.

Earlier in August, Seulgi posted a black and white snap of her clad in cropped top and high-rise pants. In her caption, she wrote, "mind the head."

The BLACKPINK member then jokingly responded to her with, "I already hit my forehead before [emoji]," to which Seulgi replied with, "no...our foreheads are precious [emojis]"

Meanwhile, Red Velvet members Joy and Yeri recently shared about how they will spend Chuseok.

"I'm planning to spend this Chuseok with my family and my pet dog Haetnim, eating delicious food. ReVeluvs, I hope you all have a Happy Chuseok! Eat a lot of delicious foods, and listen to Red Velvet!" Joy said.

"I hope that everyone I love will be healthy and happy. I want to be with them all for a very long time. This Chuseok, I think I'll find healing time while being with my family. I hope everyone eats delicious foods, meets the family members you've missed, and laughs abundantly," Yeri shared.

In other news, BLACKPINK reached another milestone. After their YouTube page became the most-subscribed music group channel, their music video Boombayah on the streaming website hit 700 million views on the evening of September 11 and became the first-ever debut music video to be able to do so. Moreover, the quartet surpassed One Direction, the former holder of the title.

The official video was unveiled in August of 2016, meaning that it took only three years and a month for it to achieve such feat.

Earlier this year as well, BLACKPINK has also defeated One Direction's number of followers on Instagram, while Lisa remains the most-followed celebrity in South Korea.