Zed wrote me several weeks ago with some research on Trollope and the "metropolitan moon". He gave me permission to post it so here goes:

The context was a spat between Trollope and the Anglican church over
Trollope criticizing how badly rural curates (or deans) were paid. As
Leonard notes, a metropolitan is an Anglican archbishop. So it's just
a reference to curates being envious of archbishops' riches. Holly, in
your comments, quotes the relevant passage, but missed that a dean is
the lowly underpaid figure.

Also, the phrase alludes to Hamlet.

Hamlet, Act I, Scene 4 (Hamlet addressing the ghost of his father).

Angels and ministers of grace defend us!
Be thou a spirit of health or goblin damn'd,
Bring with thee airs from heaven or blasts from hell,
Be thy intents wicked or charitable,
Thou comest in such a questionable shape
That I will speak to thee: I'll call thee Hamlet,
King, father, royal Dane: O, answer me!
Let me not burst in ignorance; but tell
Why thy canonized bones, hearsed in death,
Have burst their cerements; why the sepulchre,
Wherein we saw thee quietly inurn'd,
Hath oped his ponderous and marble jaws,
To cast thee up again. What may this mean,
That thou, dead corpse, again in complete steel
Revisit'st thus the glimpses of the moon,
Making night hideous; and we fools of nature
So horridly to shake our disposition
With thoughts beyond the reaches of our souls?
Say, why is this? wherefore? what should we do?

What he meant by alluding to Hamlet, and why it should be profane
(simply because he's suggesting the deans are violating the
commandment against coveting their neighbor's ox?) still escape me.

But at this point, I think it was totally not a sex thing.