Tangled Up (Error Sans X Underswap Sans)

Papyrus?!

(Why was the portal open? let's find out why)
A few minutes before

Papyrus's POV

'When I see that error sans I'm going to kill h- what's that?' Papyrus looked at the portal and remembered what it was 'A portal! I'm sure that will take me to my sans' Papyrus peeked his head inside the portal "Sans where are y- Sans?" What papyrus saw was unspeakable he saw his sans no not his sans it was the lusted part of him, papyrus always knew that sans had a lusted part to him but he never seen it before. There was one thing that he knew was to never get in the way of when his lusted part took over, so he just watched it unfold and waited till the other sans took over again. But he never did papyrus looked away 'What?! Usually the other part of him would take over by now' He looked back to see what was happening and his face grew hot, Sans had error sans on his hands and knees 'This is getting hot even though it's my brother fucking error sans......oh now i understand error sans lost control of his magic for a while so thats why the portal opened' he kept staring intensity 'so hot' papyrus said that he grew a boner 'fuck I need to deal with this' papyrus took out his ecto dick and pumped it "Hnnn~"as he heard error sans saying "US SANS FASTER!" Then his imagination went wild, he imagined his brother fucking him instead of error sans "Ahh bro your going too fast~" He heard moans coming from both of them 'I'm about to reach my limit' "Mmmm ahhh~ I'm about to c-cum" Then he heard "US sans I'm about to cum!" And a few seconds later all three came together "AHHH~" Papyrus caught his breath, he looked at them, he seen his brother go back to his normal self and come this way! "Oh shit I need to hide" Papyrus went to hide behind a pillar. US sans jumped threw the portal to go back to his universe when he jumped threw the portal it closed behind him. "Papyrus! Brother! I'm back" "S-sans Umm hey I'm glad your back heh heh" "Papy are you ok? Your acting really weird" Then sans noticed something orange on the floor and turned to papyrus "Yah I'm ok I w-was just really worried about you, now come on the queen is waiting for us" "Oh right we were going to see the queen, oh my stars were late let's go hurry!" "Ok l-let's go"