I dreamed of giving someone a key.

My dream of studying psychology is the reappearance of human subconscious, which is usually analyzed in combination with people's specific conditions. I don't know your situation, I can only make a general analysis. According to the plot of the dream and general experience, you should feel uncomfortable in the dream (the boy you like is out with friends), so this may reflect some kind of worry (combined with reality, it may be that you are worried that your roommate will be with that boy). If you are in a dream, I feel willing, and then you give her the key, which reflects that you want your roommate to be with that boy (although you may not want to)

As for the boy who moved across from your dormitory, it should be that you really like that boy and want to get closer to him.

I don't know morality. Actually, I think about it day and night. MengMeng may be a reflection of your past, but it is not a reflection of the future. Of course, if you are influenced by this dream, it is another matter.

If you like it, you must strive for a university (the landlord should be a university, right? If you are worried that your roommate will cause trouble between you and that boy (for example, she likes that boy or that boy likes her or something), I suggest you have a good talk with your roommate. Of course, never lose friendship for love.