If you find yourself in a situation where you need to tell a guy you're not interested in dating him but would still like to remain friends, you can do a few things to make the conversation go smoothly.
It's important to be honest and direct about your feelings. Tell him that you appreciate his interest but don't feel the same way. You can be as gentle or as direct as you need to be, but it's important to be clear about your intentions.
Next, you can let him know that you really enjoy his company and would really like to continue your friendship. At this point, let him know that you understand if he doesn’t feel the same way, or if he needs a little time to move on first.