[That explains some of the weirdness, if Billy thinks they're still apart. Billy had actually been better about giving him space than he expected, and probably still is trying.]

That was months ago. A lot happened since then.

[He says it softly, trying to be reassuring and not give Billy too much to deal with.]

It isn't, but they made a big fuss about it being the only way to save the universe... and it's not much good staying home if we're all going to die, I guess.