[Bahamut]

Spoiler for ...a stranger's opinion...:

…in all honesty…I rather prefer that Kirito and Asuna had sex…it would make the episode that much more powerful…
…the flow of emotions would not work as well if they just got married after confessing their feelings…usually you need to see a bf/gf relationship formed first…or the passing of time…if not…something else that is more convincible to kick it up to next gear…hence the sex…
…from near-death experience to realising/confessing their feelings…
…from intimacy to marriage…
…but then again this is just romance 101? …shrug…I wouldn’t know…

…however…if Asuna was embarrassed when she was in her undergarments then it doesn’t really make much sense why she isn’t embarrassed (half?)naked under sheets unless Kirito was there the whole time…if the following scene is implying that they were at least together in the same room…then Asuna’s moe expressions suggests they were sharing the same bed…therefore Kirito’s proposal and Asuna’s response symbolises intimacy…meaning they had sex…or oral sex...

"...oral-B...brush like a dentist!"

...whatever...

…I mean sure Kirito could have slept next door…on the floor…in a doghouse? …but that would have meant nothing…nothing to contribute to the proposal at the end…and im pretty sure the scene with Kirito saying he didn’t mean it that way was just for the audiences’ amusement to Asuna’s reaction…
…in the end of things its just sex…big deal…if any one of them dies before they get to do it…they can always find another partner…im pretty sure they won’t have a problem looking…that is if you don’t think it will add anything to their romance…