How will i know he loves me?

we are friends from past 15 years. I don't know what he feel for me. i observed that he is friendly towards me always but i feel him more than a friend or lover i have a great respect and liking which is beyond my words. i'm scared if i get married to some other how i'm gonna stay without him. i want him to speak his view about me. please help me how i can know it from him? Does he loves me alot from deep inside and nt saying me anything? I'm nt knowing it