I'm not sure I managed to convey the feeling of the sentence correctly into English but I can't think of a better way to say it right now. It basically says "This door is wide open so how can you say that?" where "that" refers to "why is everyone here".
Feelings alone won't cut it....Huh? O–of course I knew that...I–I obviously knew that too!Well... I know you two are all excited, but...You both know that you can't officially get married until you reach level 99, right?Besides, what are you all doing here...HEEEEEY! CONGRATS ON THE ENGAGEMENT!The door's wide open, what are you saying...