Stationary bicycling---will it bulk your legs?

I do Pilates but want to do some extra work on my upper legs (or buh-thighs). Squats don’t work because of my knees. I wanted to add some stationary bicycling but I don’t want to bulk up my legs….so my questions are:

1. Is it effective to use a stationary bike on low resistance (like spinning) to tone legs? Is it effective at all?

2. Does adding more resistance increase bulk? (That’s what I am assuming.)

Any info would be appreciated.