question: Who was a actor of a sibling of M1 's spouse
query: SELECT DISTINCT ?x0 WHERE {
  ?x0 a ns:people.person .
  ?x0 ns:film.actor.film/ns:film.performance.character ?x1 .
  ?x1 ns:people.person.sibling_s/ns:people.sibling_relationship.sibling|ns:fictional_universe.fictional_character.siblings/ns:fictional_universe.sibling_relationship_of_fictional_characters.siblings ?x2 .
  ?x2 ns:people.person.spouse_s/ns:people.marriage.spouse|ns:fictional_universe.fictional_character.married_to/ns:fictional_universe.marriage_of_fictional_characters.spouses M1 .
  FILTER ( ?x1 != ?x2 ) .
  FILTER ( ?x2 != M1 )
  }