HELP 10 POINTS BEST ANSWER.... what is this? Does he like me?

So basically I started hanging out with a mutual friend over the last 4 months. And over time, things have developed into a closer friendship than I expected. Something that started as a late night bite to eat turned into him texting me good morning every day. Hanging out on other occasions alone, him calling me and hinting things giving me pet names etc. No one has expressed feelings for one another so it s at an awkward stage. But now whenever he hears about another guy trying to hit on me he gets a little upset. When we text and a guy friend is mentioned by me I get a lot of "errrrrrrrrr" and "hmmmmm" I do like him a lot but I was always afraid to say it because of fear of rejection. We were talking the other day and he messaged me a heart out of no where so I sent him one back. He left me on read. I felt so stupid but then the next morning he texted me good morning and everything as if nothing happened and sent a heart AGAIN. I I sent one back but yet again he leaves me on read, I understand that when he's talking to me he's working. He keeps initiating these damn heart texts but then sometimes he will disappear for a few days then come back and send more hearts while we're texting Also whenever he's joking around he says I'm just kidding "friend" he doesn't always address me as that but there's those moments. Ugh I don t know how to read this situation. Why would guys do that? Does he like me?