He try's to mate with female potbelly molly, but I don't think anything has happened. Can that happen. I had a female dalamation and he was very aggressive with her, ignored her mostly and pursued the potbelly molly.
Do you have any aquarium salt in the water?
Mollies will 'shake' or 'wobble' if they don't have some salt.
Or that could just be his way of taking a break.
The fish is trying to attract a female. It happens with most fish. He'll be okay.
hope it helps:)
