My 12 yr old sister is so hot and I’m jealous

I’m 21 and I get jealous every time I see my 12 yr old sister wearing a fitted dress because I can see the outline of her new boobs. I don’t have a problem with her wearing things that are a bit tight, but I get jealous because I think the boys in her class can see the shape of her tits and I want to hide her from everybody. <br><br>I don’t want any man other than me to see her like that, or to touch her and I don’t know how to stop her from dressing like that.<br><br>How do I stop myself from getting jealous about this and how do I let her know how I feel about it?