rastuživati

1. to sadden; to upset
   Ta pesma me uvek rastužuje. — That song always makes me sad.
   Ne želim da te rastužujem lošim vestima. — I don't want to upset you with bad news.
2. (rastuživati se) to grow sad; to get upset
   Uvek se rastužuje kad gleda stare fotografije. — He always gets sad when he looks at old photos.

The perfective is rastužiti; present tense: rastužujem, rastužuješ.