How long does it take for a guy with bad intentions to give up?

Some guys can keep chasing you for years, even if they have bad intentions. The reason is, they are still getting it from other girls, but if it doesn't take them much effort to keep chasing you at the same time, they will. But if he's willing to really go out of his way for you, taking you out on nice dates, giving you a lot of time, etc., without getting laid, he could really like you. But make him really work for it, hold out as long as you can.