how do I tell him?

I’ve been sleeping with a friend of mine for a little over 4 months now although we only really became friends about 8 months ago. We knew each other before through friends but never really interacted until recently! So my problem is is that I think I like him a lot. We talk all day and all night long when where not together and hang out all the time. Sometimes our texts can get pretty flirty, but I don’t try and read into them because I don’t want to get too excited and fantasize. Now I feel like I want to say something about my feelings for him but I don’t want to freak him out and just in case he doesn’t feel the same, I don’t want to lose a friend. Any advice on what the best way to go about this is?