How to say sarcastically “Wait for a long time (perhaps forever)”

Question

Which one of the following phrases can be used in the context below in natural English:

• A) Let me go! I won't come along with you. I don't like the company of such people.
  B) But believe me; they love you; I don't know why you're spiting me, but I'm sure you'll enjoy it. You just try once.
  A) I won't come. I'll stay right here!
  B) Ok; suit yourself! ........................... (said sarcastically)
  

1) Stay / wait there untill grass grow under your feet.
2) Stay / wait there untill cows come home.

I need to indicate: "stay / wait there for a long time (figuratively forever)"

Unfortunately, dictionary definitions couldn't help me to distinguish these two similar phrases and also they do not show me whether these are archaic or not!

Answer 1

"Letting the grass grow under your feet" is a saying about procrastination, so it does not really fit.

"Until the cows come home" does mean a long time, but not indefinitely - the cows come home each day (it refers to them returning each morning for milking after being put out to pasture at night).

"Hell freezes over" is normally used when saying that something will never happen, for example if someone says [x] will happen one might reply "on that day hell will freeze over". This could be adapted and recognisable but it would be a slight deviation from normal usage.

The most common sarcastic saying would be simply "You'll have a long wait". I know it isn't very detailed, but when people say that it is not only sarcastically, but knowingly, and usually when the other person has not listened to advice.

Other sarcastic sayings to indicate that someone may be waiting a long time include "better make yourself comfortable" and "don't wait up" (which means they should not expect to see you before they go to bed).