[He's...he probably does understand that Megami can't possibly be talking seriously about this, but at the same time the thought of it- the serious thought of not being "alone" anymore in that sense- resonates deeply with Poseidon.

So, without a hint of irony, he holds Megami up to eye level and says:]

It is true. I did promise that. ...and here I thought most gods were fickle, yet now I must make such a commitment...