Who kissed B2ST’s Yoseob?

B2ST’s Yoseob has received a big kiss from someone!
KBS’s “100 points out of 100″ uploaded the above picture onto their Twitter, and left a mysterious message: “Lipstick on Yo Seob’s cheek! Who is the owner of that kiss mark?”
In the picture, fans were able to see a pouting Yoseob on the set of “100 points out of 100″ with a prominent lipstick stain on his cheek.
Yoseob later mused, “Come to think of it, I received kisses from three people today.” Fans replied, “Who is it?”, “Did you like it?”, “You should have received permission from your fans first!”, “Whoever it is, I’m jealous”, and “I can also kiss you..”
Who do you think his kisser could be?

cr: allkpop