Sex Amongst the Maiar (and the Other Beings in Arda)

[Galin]

It was said that the Valar usually took the shape of the bodies of Elves and Men -- of majestic but not gigantic stature (and in some degree radiant), vested in robes expressing their individual natures and functions.

Also, that the Valar and Maiar could assume other shapes (Yavanna as a great tree and so forth, as in Silmarillion), although it's noted in RGEO that the Eldar seldom saw other inhuman forms taken by the Valar. I initially thought that we could easily say the same of the Maiar, but then I remembered this little interesting note from JRRT in Morgoth's Ring: 'Living things in Aman. As the Valar would robe themselves like the Children, many of the Maiar robed themselves like other lesser living things, as trees, flowers, beasts. (Huan.)'

... which has me wondering a bit. Anyway in notes regarding the word fana(r) Tolkien seems to describe the fanar of the Valar and Maiar, but in RGEO (published by JRRT himself), unless I missed something, he speaks there of only the Valar, technically.

In posthumously published notes there is an interesting distinction:

'But the Elves of Valinor asserted that unclad the Valar were perceived by some among them as lights (of different hues) which their eyes could not tolerate; whereas the Maiar were usually invisible when unclad, but their presence was revealed by their fragrance.'

*(...) The Maiar corrupted by him [Melkor] stank'

JRRT, Words, Phrases and Passages

This bit also does not appear in RGEO, in any case.