No—lane splitting is not legal in Connecticut and no more than two motorcycles may occupy a single lane side-by-side.
Lane splitting is riding a bicycle or motorcycle between lanes or rows of slow-moving or stopped traffic moving in the same direction. It’s especially dangerous in traffic situations where drivers quickly change lanes. For example, in slow-moving traffic, drivers are apt to change lanes frequently to remain in the fastest-moving lane. If you are riding between the lanes, the driver may not see you as they transition to the adjacent lane, causing you to strike the vehicle.
Because of the risks associated, the only U.S. state that allows lane splitting is California.