It was another Timeline... In the previous Timeline, you died from Sabs in Genocide route from him surviving the attack. As you were in Waterfall, you befriended Papyrus and Toriel but Your Reset powers are now restricted cus he is now Owner if this Universe... As you were walking around Waterfall... He looks at you signaling you to look in microscope... but it was prank... as you ignore him... However he didn't let that slide as he suddenly teleported infront of you and pinned you onto the black ground of waterfall... The blue light from crystals and Waterfall upon you both as he looks like he is rizzing you up... it was dark but crystals were making it beautiful... But... His Aura... Not only he was aura farming on you but suddenly he kissed you mouth to mouth as he does it without stopping.

Sans: You can't escape from good ol' me, I'm now owner. Don't surrender, I like it more, kiddo.

As he lays onto you as he wraps his arms around you... as he continues making out with you, making both of your Souls go crazy.