This is Norton the mailman. He’s got a crush on Squidward.
In “Squid Plus One” he hands Squidward a letter and impatiently waits for him to open it in front of him.
When Squidward opens it, it’s an invitation to a fancy event. And he can bring a plus one!
Squidward is confused what a “plus one” is, so Norton explains (and also is now standing in the middle of Squidward’s house).
He says that a “plus one” is a companion you bring to an event. Then he makes this face.
Squidward does not get the hint and sends Norton away.
So, Squidward gets an invitation, and even though he knows of the event, he doesn’t know why he’s invited. But Norton seems to know what’s going to be in the envelope before Squidward even opens it.
I think Norton, who is too shy to ask Squidward out, organized the whole thing, and shot himself in the foot because Squidward is oblivious.
In “Under The Small Top”, Norton has a package for SpongeBob. He mistakenly gives it to Squidward, even though it clearly says SpongeBob’s name on it, and Norton knows SpongeBob by name (we know this because he talked to SpongeBob a minute earlier).
As soon as Squidward opens the door, Norton ogles his outfit.
It’s the perfect time for him to show off is matching leg warmers.
He’s trying to bond over this, but Squidward again is oblivious and annoyed.
Squidward doesn’t get any other mail that day. So if Norton hadn’t given him SpongeBob’s package “by mistake”, Norton wouldn’t have seen Squidward that day.
My theory is Norton needs an excuse to come over, because he knows Squidward is working out to an exercise program that day, which is on at the same time every week. And Norton know this because he’s spying on Squidward. Which is the only reason he owns matching legwarmers and just “happens” to wear them that day.
It’s too bad Squidward’s gaydar is broken. People who are interested in him keep showing up at his doorstep and he thinks they’re just trying to annoy him.