Does stretching often, help to prevent bulking up?

I want to achieve skinnier legs. Before they were just fat, but now they are getting muscly and bulky. I've heard that stretching can prevent this. Is that true? And are there any common methods to prevent this unwanted bulkup? Thanks!! :)

that was a dumb place for a comma

My right leg hurts in the upper part but when i stretch it out it still hurt and i don't know what to do....

No, stretching will not prevent bulking up. If you don't want to bulk you need to avoid workouts that may encourage muscle growth on your legs. It depends on what workout you're doing at the moment. If you're doing regular resistance workouts then yes, your muscles may bulk up. The trick is not to regularly increase intensity/load or decrease rest times for whatever exercise you're doing that involves your legs. By doing so, you may encourage muscle growth. BUT do remember...more muscle=bigger fat burn. No excuse to join the ranks of Arnie, but enough to stay toned So basically, keep exercising, don't push the cap on exercises that train your leg muscles and eat calorie neutral diet