Another mysteriously unknown RDBMS. Your Syntax is perfectly fine in PostgreSQL. Other query styles may perform faster (especially the NOT EXISTS variant or a LEFT JOIN), but your query is perfectly legit.
Be aware of pitfalls with NOT IN, though, when involving any NULL values:
Variant with LEFT JOIN:
SELECT *
FROM friend f
LEFT JOIN likes l USING (id1, id2)
WHERE l.id1 IS NULL;
See @Michal's answer for the NOT EXISTS variant.
A more detailed assessment of four basic variants: