Board Thread:Questions and Answers/@comment-189.182.75.248-20170406031815/@comment-29759785-20170406063430

Don't worry, as of volume 18 Kirito x Asuna relantionship is not affected in any way. There are still as happy couple as ever. Heck, in volume 18 they got two (IIRC) sweet moments.

If you want to know more I strongly suggest reading this thread:

http://swordartonline.wikia.com/wiki/Thread:55074

But, be aware, that it contains many spoilers from volume 17 and 18.