Hi Florine! Your English is great. :)
I couldn’t agree with you more! *_* Mesut is very very very cute and beautiful!
About your question, I think Mesut is extremely close to his cousins who often visit him in Madrid (and even seem to live with him there at times) but if we don’t count family, I’m guessing that Sami is a very close friend of his. They came to Madrid at the same time and only had each other to talk to and rely on. I believe they became very close during that time. ♥