maximum Y I K E S!!!!!!!!!!
like, they say Frisk doesn't have a clear age but they have been called child( "innocent youth", Toriel saying they didn't want them to grow up stuck I the ruins, them being recognized as a child because they were a striped shirt, did I mention how small they are and how they are the same size of Asriel and Monster Kid two CHILD characters??,
"OH BUT SANS IS THE SAME SIZE"
yeah but Sans is a adult, which is obvious because he is able to get a job and even addresses Frisk as "kid".
ugh, I hate undertail.
EDIT: YOOOO DIDNT WANT TO MAKE A JOURNAL SO I PUT THIS INFO ON HERE BUT HERE TO GO UNDERTAIL FANDOM/PEOPLE THAT THINK FRISK IS A ADULT/ FRISK X SANS SHIPPERS

//I didn't make the screenshot, got off Tumblr//
BUT THERE YA GO. FRISK IS A CHILD FRISK IS A C H I L D.
and before you say "BAWWW YOU CANT READ THEY CAN BE ANY AGE"
ya they said ambiguous, but that doesn't change the fact that they ARE depicted as a young child. Which only means they can be up to 5-12, possibly 13 too I guess.
NOW STOP DRAWING GROSS PORN AND SEXUALZING THE CHILD.
CHRIST IS WATCHING