This how Frisk and Chara look here were 18 years old, female and girls so they are not children: https://www.deviantart.com/ayloulou/art/Chara-x-Frisk-678199825, or if only Frisk: https://www.deviantart.com/ayloulou/art/Frisk-663719389

Female Sans: https://www.deviantart.com/peeman21/art/Pervs-like-you-should-be-burning-in-hell...

Female Papyrus: https://www.deviantart.com/maxton145/art/Fnia-Papyrus-NSFW-rp-images-is-Mairusu-...

Toriel (Only if you picture like this): https://www.deviantart.com/balloonfuckboy/art/Fnia-Torie

All girls are unaware, sometimes...