If you read 不许联想 you know what it is.
If not, here’s a hint: over the weekend I heard Tony Bennett singing an old standard on radio, which starts with this:
Someday when I’m awfully low
When the world is cold
I will feel a glow
Just thinking of you
The song stuck in my head for the last few days, and I remembered 王大福吐奶 just now. I think my version is more literal and Beijinger, but less meaningful.