ludovati

1. colloq. to romp; to fool around; to party wildly
   Deca su ludovala u dvorištu do mraka. — The kids romped around the yard until dark.
   Ludovali smo na koncertu celu noć. — We went wild at the concert all night.
2. colloq. (za + instr.) to be crazy about
   U srednjoj školi je ludovala za njim. — In high school she was crazy about him.
   Moj sin luduje za fudbalom. — My son is crazy about football.
3. (often disapproving) to act foolishly; to act recklessly
   Ne luduj, ne možeš da daš otkaz bez ikakvog plana. — Don't be foolish, you can't quit without any plan.

In the sense 'be crazy about' it takes za + instrumental: ludovati za nekim.