How do i know if a boyfriend would like to marry me in the future? ?

i ve been with a guy for 2 years and a half. we've broken up only twice officially and he is the one that comes back to me afterwards. Our first break up lasted 2 weeks and then he called me the second one lasted one week. The last time we broke up was because he said he wasnt sure if i was the one but a week later at a friends' kickback he offered to give me a ride by the end of the night and when he parked he told me that i was what made his life happy and that he didnt had anything to look forward to without me. I wasnt sure about getting back together after a week but then he told me that he was just afraid of losing me and that perhaps i was "the one" he just was too afraid to see it. I found out later that he had bought condoms before we got together and last weekend we tried to have but i was too afraid so we didnt end up doing it. we're both virgins and legal enough to drink. I spend the night over at his house frequently on weekends. he ignores the subject when his married friend same age as him mentioned to him about giving me a "promise" ring to get married in the future already. Is this guy planning on marrying me in the future or is he just trying to get sum for the moment? he still lives with mom.