Wonder Girls took a trip down memory lane during their time on MBC's 'Sunny's FM Date'! The Wonder Girls members and Girls' Generation's Sunny talked about a time when they switched songs with Wonder Girls performing "Kissing You" and Girls' Generation performing "Tell Me"!

MC Sunny asked, "Wonder Girls have tried a lot of concepts. To the point where there isn't anything you have tried. Among those, which concept did you like best?"

The members laughed as they had a bit of trouble thinking of their favorite.

Yubin replied, "The concept where we looked prettiest is this concept. Do you remember back when we switched songs? Girls' Generation's 'Kissing You'. We had never had a bubbly, youthful girly concept before, and that was our first and last time, so I remember it."

"I remember when I sang the 'omona' part, I acted flirty," Sunny said as she reminisced singing Wonder Girls' "Tell Me". 

Sunmi added, "You lent us those things, the candy," as she laughed remembering. 

Sunny then stated, "Even up till then, we weren't close but we wanted to be close. We were shy [with each other]."

You can see the girls talk about that part at the 14:45 minute mark above.

SEE ALSO: 'Gee' becomes Girls' Generation's first track to surpass 100 million Spotify streams

And anyone out there remember when this happened? It was absolutely 'daebak' at the time and still entertaining to see now!