Lagertha knows she shouldn't be letting any of this happen. She knows, and yet she can barely whimper when Ragnar's lips are placed on hers again after so many years of kissing someone else's. That thought is unwelcome, an intruder of the moment she is stealing, and she tries to push Ragnar away, her hands on his shoulders, but she doesn't push very hard. He knows this, and he needs not insist nor press with any more force; on the contrary - his kisses have grown gentler, more tender, as though meant to heal a heart long past healing. He does not know what exactly he's feeling right now - it's a bit of everything, really, and he does not care to decipher his confusing heart - all he knows is that he's missed her, and that is enough for him, in this moment at least. He cannot bring himself to even try and think of any consequences, for the world entire does not really exist now, and so he kisses her and kisses her and kisses her... There's only him and only her, and her lips now moist from the tears he isn't sure when exactly she started spilling. He can taste the salt, and it hurts so much it genuinely surprises him. He hasn't felt this guilty ever, not even when he lost her, not after everything he did. But now - now it's like a dagger in his chest he does not deserve to pull out.
''We should not do this,'' Lagertha does not say, but Ragnar hears her, and yet he kisses her even more - tenderly, gently, lovingly.
''You are married. This is wrong. I will not be this kind of woman,'' Lagertha does not say, but Ragnar hears it in the way her fingers are twitching on his arms, as though unsure whether to grip more tightly or to pull away.
''This cannot last,'' Lagertha does not say, but Ragnar hears it more clearly than anything else, and it hurts him the most of all.
Lagertha does not say anything at all, not a word. There is only a whimper.
That is usually how a world comes to its end - not with a bang but with a whimper.