Question

alone, i am the 24th letter of the alphabet, with a friend i am 20, and with another friend i am dirty. what am i ?

Answer 1

x,  It is the 24th letter of the alphabet, XX in Roman numerals is 20, and XXX is a label for movies that are "very inappropriate"

Answer 2

X is the answer. Two X’s make XX which is Roman numerals for twenty. And three of them is XXX which is inappropriate