Aradia ==> You are amused and tell him as much

You're laughing too hard to actually get the words out, but you can tell he gets the message anyway. His spluttering only makes you laugh harder.

"Be careful, he might see blocking him as black flirtation," you finally manage. It's strange to think that only a sweep ago it would have been impossible to imagine that one day you would tease him so easily, laugh with (well, at) him so freely. Of course, a sweep ago you weren't exactly in a state where you were laughing at anything, but still. You happily push a little further, "Then I might need to get jealous about there being another black interest in your life."

But your light mood is brought to a halt by the sudden shattered look in his eyes. "Aradia, you still-- that is, I thought--" he stammers, and it's just as strange to know that you can hurt him so easily with an ill-chosen joke as it is to be making those jokes.

"I was just teasing, Equius. Don't worry, I haven't been having new black thoughts about you." It felt too good to be alive, to have him be alive, to be back on an Alternia that was slowly changing for the better with the Empress's malignant influence removed, for your heart to harbor much hatred towards anything at all.

"Ah. Teasing. O-of course," he replies, but still looks uneasy.

Do you...
Reassure him with a kiss?
Tell him about your expedition to take his mind off it?

Aradia ==> You shudder and express pity for him having to go through that

You shudder. You can only imagine what Eridan had in mind and none of it at all can be described as 'romantic' or 'sexy'. You do feel bad for him, but you feel much worse for Equius.

"I am sorry you had to endure that," you say. "Next time I will find a more... appropriate messenger."

"It is alright. If it was not me it may have been someone else, and I udder to think of him coming onto you or Nepeta as such."

You freeze, and apparently so does he.

"Me or Nepeta? So you would actually care if he came onto me?"

"Of horse, I mean, erm, of course. You are my... friend."

It doesn't escape your notice how long it took him to get the work out.

Confront him about that