Persistent

persistent | pərˈsistənt |
adjective
 1 continuing firmly or obstinately in a course of action in spite of difficulty or opposition : one of the government's most persistent critics.
• [ attrib. ] characterized by a specified habitual behavior pattern, esp. a dishonest or undesirable one : they accused officials of persistent discrimination.
2 continuing to exist or endure over a prolonged period : persistent rain will affect many areas.
• occurring repeatedly over a prolonged period : persistent reports of human rights abuses by the military.
• (of a chemical or radioactivity) remaining within the environment for a long time after its introduction : PCBs are persistent environmental contaminants.
3 Botany & Zoology (of a part of an animal or plant, such as a horn, leaf, etc.) remaining attached instead of falling off in the normal manner.

If I had a choice, I'd prefer to go for the third option.

People should know well enough that I'm not keen on giving out other people's number unless it's for documentation or business purposes. For your own pleasure, you shouldn't actually ask me. I won't give it.

If you want a number from me, tell me the reason why. If I see it is suitable, then I'll give it to you, more often after asking permission from the person whose number you want.

I absolutely DESPISE it when you just state "Hey, can I have xx's number ah? I need to ask him some stuff."

Uh ... so? What's the some stuff you need to ask? I'm not asking you to tell me in detail like "Oh, I need to be more knowledgeable in my sex life so I need to ask him some directions on how to enhance my dick."

And then you bug me like hell over it. Even to the extend you keep calling my handphone? If it's so urgent, state your reason first. Loser!