So i (m) was running in the park yesterday around 11pm(i like running latenight because there are less people and the air is better).

The park isnt very well-lit and was completly empty except three 16-18y old probably slightly drunk girls sitting on a bench smoking.

The first time i passed them they said "hello" and i replied "hi".

The second time i passed they said "hi" i said "hello".

The third time they said "not so fast"(sounded like sarcasm but i wasnt sure).

Now the fourth time i was running very close to them suddendly turned to side and yelled "buh"

.... ive never heard screams like that before.

Wanted to stop next round and explain that it was just a joke but they were gone.