Kirito is not very assertive and does not give his female friends the boundaries of the rules, he is too nice to everyone. Despite the girls knowing that Kirito and Asuna are a couple in love, they will always be together. When it comes to harem, you know the creators do it because it is marketing, it is just a pseudo-harem, because the girls do not pick up and steal Asuna's boyfriend like other harem anime. In 2024, LN Sword Art Online Light Novel Volume 28 (Unital Ring VII) was releasedIt depends on the genre of the anime. If the characters are adults then acting like that is just weird. But if the anime character is a teenager then of course the tv censors don't want them to seen having sex. Most teenagers are seen as dumb and indecisive because they are young and inexperienced. That is true in most medium not just anime.
Interesting fact about that SAO moment you mentioned. Asuna and Kirito did have VR sex that time so canon Kirito is not impotent and a virgin even at the beginning of SAO if you count VR sex.
This is based on canon SAO relationship. Kirito and Asuna have always been the perfect couple. Neither of them was ever interested in anyone else. This is actually one thing I don't like about the series. The author clearly wants the couple to stay together but he keeps adding girls that try to get into Kirito's pants. He never wants to and the girls are just there to give him a "harem" he will never uses. It is like the author is trying to have a harem and one true love romance at the same time which is annoying.