Can I make him desire me again?

Hello! Im seeking advice upon quite a delicate matter. I was on a 6-month student exchange programme last year in Austria where I met this wonderful guy. He was not on exchange but doing a full degree there. We got interested in each other immediately and hung out together for about a month with mutual friends and having a lot of fun (as friends) . Then we decided to have a short-term relationship for as long as I would still be there. It started out only sexually, but then developed into something very passionate and emmotional. I have never felt happier in a relationship. Everything was perfect, even though we were from different countries (Greece and Italy) we understood each other, did almost everything together- both alone or in a larger group of friends- had a mutual respect and caring for each other that I havent experienced in previous relationships. And making love together was ultimate chemistry from the first time to the last, and all the above emotions surfaced during our nights together. We parted when I went back to my own country and spoke to each other on facebook or skype sometimes, but not too often. Now I have returned to Austria to pursue a new degree after an absence of 7 months. Obviously I hadnt seen the guy for 7 months either. when I informed him of my return he was overly excited and came to see me immediately. we talk every day and go out at least 3 times a week, we live in the same neighbourhood and became the center of a new friend group that we created together. But only as friends. It reminds me a bit of our first times together before the erotic thing came out. I can see that our general bond is stronger than ever and we trust each other and care about each other. Im also sure that there is an underlying sexual interest towards me because we flirt a lot with words, and 100% sure that he is not seeing other girls. But we are just friends. What can I do to make this sexual desire come out of him again? I cannot tell if he has stopped being interested in me in this way or if for whatever reason he is scared to show me his real feelings thus keeping it friendly. I need to find a balance between showing him that I like him but not being too obvious, or else he will lose this thrill of the chase and friend-zone me forever. And also I dont wanna completely scare him and drive him away from my life completely, because I truly love him. On the other hand I need to show him my feelings because then how is he even supposed to know that I dont see him only as a friend? This is such a difficult situation, can you please give me some advice?