How to deal with an overprotective twin brother?

Well I have a very very overprotective TWIN brother which makes it even worse than you can imagine. So since teachers think we would be more comfortable around eachother they always put us in the same classes and makes us sit next to eachother its so annoying whenevwr another guy like talks to me or tries flirting with me he like scraes them off and its really annoying I just want a way of telling him to back off and he never lets me and my boyfriend have 'alone' time I mean I love my brother and everything he just needs to back off a little and I don't know how to tell him. Any advice?

I see how that can get pretty bad. tell the teachers that you dont want to sit by him in every class and if needed then switch classes and tell your twin that its your personal life and he doesnt need to be in it all the time and that your glad his there but you need your space.