they wanted to fuck with him and steal his lip gloss so they could wear it and make out in front of him without letting him touch. if beomgyu were to cum, tyunning would exclude him from all sexual activity for the week, so beomgyu gave his most herculean effort to control himself. they’re all surprised that he kept his cool until all the lip gloss was wiped off and replaced with spit. and he pays them back with their own special type of lip gloss afterwards. with a pearl necklace to top it off.