This form is called “rictameter” – 9 lines, beginning with 2 syllables, then adding 2 per line until there are 10 for line 5. The lengths then return back to 2 syllables, where the first line is repeated. Not easy, but please add one in the comments or link back to me if you post one on your blog!
down with silken
ties that spread my naked
body. At your mercy, nipples
swelling, cold fingertips caress my sex.
Later – spent, fulfilled, exhausted –
you’ll untie me, enfold
me and all night