Well, stop having sexual relations with the person for starters. Then, once they ask why the sexual relations have stopped, and they will, tell them you’re breaking it off. That’s pretty much all there is to it.
Oh sure, you can have feelings of regret or question your decision afterwards, because everyone does. You can even add a few excuses to the breakup announcement if you want, because why not. If you need a list of bull shift excuses, just use the same old lines everyone uses. Stuff like this…
– It’s not you it’s me.
– You deserve someone better.
– I just need some alone time for now.
– I need to focus on work / school / my diet / my goldfish.
– I only love you as a friend.
– I feel like I’m holding you back from living your life.
… and there you go.
Tell them you’re no longer interested in partaking in this type of relationship and are looking for something more serious.