Shit will not end well.
At first I was like "good, they settled that pretty quickly without the usual will they, won't they runaround". But before the word "good" had even finished coming out I said "ooouhh No wait... Bad maybe? It's too soon. It's too much, too cheerful, too soon." Like he's gonna get to retire to an idyllic life away from fighting? No, he's the protagonist and it's too soon for the show to end. Between all the promises of sticking together, protecting each other, not dying, Asuna's ominous dreads and Kirito's advising Asuna to join a guild in the first place we have all the ingredients for a tragedy.
Did they go back to the guild and report what happened? Cause if they didn't the guild is probably gonna come calling. "You murdered two members of the guild." "No we didn't." "Who says, the renegade girl who wanted to leave anyhow and the stranger who wanted to take her?" That won't go well. They probably can't beat the whole guild let alone the fact tank dude can take Kirito one on one. Or could hire assassins. I hope I'm wrong, I really do. Because I can see it going that way.
Maybe the guild will just forget about them, or maybe they'll get attacked ending happy-peaceful-time but both survive... Damnit I'm speculating... And I hate speculation. Come to think of it, they kinda threw me a curveball by not dragging that romance out forever, maybe they'll throw me another one and avoid the obvious tragedy.