How many letters does the top answer for “sexual relations between a man and a boy” have?

The most common answer is pederasty (9 letters).

Crossword clue: sexual relations between a man and a boy

1 answer found in Letterora's clue database (Wikidata facts, Open Trivia DB, WordNet and Webster definitions — all licensed sources).

pederasty 9 letters wn-def

sexual relations between a man and a boy

of homosexuality between a man and a boy 50% similar → pederastic