How to discourage suitors

Thankfully I do not have the problem of males who wish to get in my pants. (If I do, I am somewhat oblivious to it.)

However, should I encounter a persistent one whom I am not overly fond of, but do not wish bad intent with, who ignores my insistence on not liking him that way, the following line will be of great use:

"You're like a brother to me."

For those closer, whom I wish to keep close relations and open trust with:

"I love you like a brother."