Dream had had a party of elegant music and waltz at the star-sanses base, and had invited several AU's. His brother Nightmare found out about this and sent Cross to take advantage and steal the purple vial with X-Gaster's soul from Ink's room while he was distracted, without anyone noticing:

"........"

Cross managed to infiltrate the people, since if they discovered him he would have serious problems with Nightmare, his boss. Cross decided to use his strategy and planned a way for Ink to fall into his trap and steal the vial without being seen. Cross approached Ink from behind and whispered:

"Would I have the pleasure of dancing with you?"