Mollys fighting?

Hi. Some advice please. How do I k ow if my mollys are fighting? They going round in circles with each other and have been for the last 10 minutes

 

I don't know much about mollies, but would you suppose they are breeding?

 

I think they are 2 males and 2 different types of Moly. Never seen this behaviour before with them

 

How large is the tank?

 

125 litres. Had one for over a year and the other 3 months