I went through what you are going through too. It is much better if you trap your little boy and get him all vet checked, neutered, and shots, flea treatment, wormed and everything he needs.
You don't mention where you live, but if it is in an area where winters are hard, I can tell you from experience that you will want to take care of your boy and his needs before it is too cold outside.
It is hard to trap for the first time, but the people on this site can help you through it. They helped me and it was the best thing I did.
I've had my feral boy (and his GF LOL) for almost 2 years now. He lets me brush and pet him and he loves to snuggle. I have not brought him inside yet, but I built him a house outside and I plan on trying to bring him in this winter if possible. He does come into my house to eat during the cold months and I just shut my kitties into their own room and feed them at the same time there.
Both my feral boy William and his GF Ace let me put Frontline on them too. They have become completely trusting. It just takes time and establishing a routine as well as talking to them and playing with them, just as you would your indoor kitties. The only thing you can't do is pet them before they let you.
There are a lot of solutions to your care for this little boy. It just takes time to think it all through. I hope this has given you some thoughts and ideas. I will be happy to help you with anything more you need
If you will keep your boy outside for now, just be sure to prepare for him to live there. The worst thing is getting attached to him and then seeing him soaking wet from the rain, or injured, or freezing in the cold. I can help you with that too, just let me know. There are also lots of links for ideas. I am rushing off to meet my hubby now but will post more later :-).