The way you describe it, I think he does, too. Try asking if he would like being roommates, sharing an apartment. For starters, it would mean each spending less on rent and other shared expenses like utilities--especially helpful during times of high inflation. Friends of all kinds do it all the time, so that can be an opening to observe his reaction.
If he's enjoyed fucking you so much and for so long, then he thinks of you as more than a fuckbuddy. But, being a guy, he's probably reluctant to admit it. You know him better than most. But, I wouldn't just blurt out your feelings quite yet because that jolt will probably be too much. I would try exploring conversation topics that may lead to being able to ask something like, "How do you think that might work with you and me?" How much other time do you spend with him? Any chance of just walking up behind him to hug him? If he asks why, say something like, "Just because" since you don't want to shake things up but build on them. Or, maybe if he gets pensive, you may be able to ask indirectly.
I've mentioned elsewhere how a 24-year-old desperately wanted a safe, dry place to stay during a thunderstorm in May 2020; after drying off, he had nothing dry to wear, so I told him I always sleep nude to which he admitted he did, too; being in a stranger's home for the first time & recently homeless, it was his idea to sleep on the floor. About a month later, he started visiting regularly during the day and never saw me wear a shirt of any kind until November, so he felt comfortable also be; as soon as he learned I'm a nudist, he often would strip nude, too, before he saw me when horny. In mid-July, he was sitting on my bed occupying himself, not doing much, while I was on my computer when he surprised me by quietly asking, "Do you want to fuck me?" After a few seconds, I replied, "Yes! I've wanted to since the night we met." More happened, including his sharing my bed many nights over the next 1½ years. We had a lot in common and not just sexually, which mostly explains why he kept returning after being away for awhile. Despite, or maybe because, I'm nearly 3 times his age, and despite what I knew about his recent background, I knew we could be great roommates in an open relationship; he might want his own room to retreat to, but he would prefer sleeping with me. But, especially with my limited income, he would first need to get a permanent, full-time job with reliable income so that he could be an adult and pay his half of shared expenses. You two are already fucking and regularly. But, look for a similar time or times to work up to asking or otherwise learning how he feels.