How do I nicely reject a guy?
I heard that a friend of mine wants to confess to me, but I do not like him in that way. For sure I am rejecting him, but at such times, I tend to unintentionally use words that sound rude to others but all right to me. He is a nice and a sensitive guy, he suffered from depression for a while as well, so I am really scared that my rejection will have a bad and deep affect on him, especially if I use my rude way of talking for the rejection. Certainly I tried changing but its just something I do not think I can change. To be honest, my personality is the kind that hates seriousness and wants fun all the time, a person like me would have such a response if someone confessed to the: "haha! oh my god! you like me!? wow!!" and just go on laughing. Now I am certainly not doing that which is why I am asking, how? What's the right way to reject? This whole thing is a mess, actually. I have a guy I like, and we three and other friends are in a group chat, he would leave the group chat whenever I and the guy I like talk because he feels jealous, but out of embarrassment he never stated the reason as to why he is leaving the group, but I heard this from a friend, to whom he told the truth.
Another thing is, I wonder if he will want to stay friends with me after I reject him. I do want to stay friends with him but I know its difficult because I was friend zoned once before as well.
SO MY HEAD HURTS! HIS WHOLE THING IS SOMETHING MY LITTLE BRAIN CAN NOT DEAL WITH! Advice?
Thanks in advance