Well! Wait a minute, I need to finish this last spot. [Papyrus doesn't just turn to do so, though. He wants Sans to be prepared for helping, really prepared, as much as he can from here.] And then...

It's not need. [He blusters this, a little defensive and still uncomfortable. The thing about welding behind the curtain is, he still hasn't gotten used to any non-roboticists looking in at the intricacies of his robotic parts.] I could do it myself. I was ready to do it myself! But since you're offering... it'll be faster, if you help me screw a few spots in place. And connect a few wires.