Just a hunch. They were pissed at the car in front who was driving with caution due to the conditions. Or, they were a hot blonde sick of lock down and wanted a a shag, and gets turned on by cyclists..where's my bike? :) Stay well mate.
This car is driven by a vile wench called Rebecca. She pulls out in front of people to try and cause an accident, then blocks them whilst hogging the outside lane at 30mph and dabbing the brakes. Rebecca is an overweight slag who smells of sweat and lard. She should give up driving with immediate effect.
It's not a playground mate. The other rider might have been revving to alert you of their presence.