i'm in between when it comes to your final three lines; one side likes it because of the truthfulness displayed so nakedly: a fitting volta-like expression, if you will; the other doesn't because it seems like it's already implied... and, well, soppy as you said. but i'm always in conflict about things like this so my opinion means nothing.
'in the den' or 'in its den'? the latter is more inclusive.
my one other nitpick is the use of your word 'truncated': it fits, but doesn't. either think about dropping or replacing it? also, i find you have to be careful when using 'like' similes (as you've used two in successive stanzas here)... often times it's better to disguise it, which something like this will do:
"The duvet dipped into nothingness,
a sheer cliff-face."
this both cuts out seemingly unnecessary words and also distills it right down; still a comparison, but a bit more subtle, don't you think?
i wonder what your poems would be like if you stepped outside of these chunky four/five line stanzas? just something i've noticed you stick to, and which might enable you to be more free if you were to experiment with linebreaks and spacing. everyone needs a creative push, i figure...
i enjoy the sentiments and imagery of this poem: a love shared, defined, given breath. the universality of this is what appeals the most, i confess...
I like the whole conceit(metaphysically speaking of course) of transmuting impressions from the various senses into pigments on canvas. It's a great idea. I smiled a bit at the simile of the otter in its den, as though we're all perfectly familiar with how otters sleep in their dens. For all we know, they always lie flat on their backs with their four legs splayed wide. No I jest.
Haven't we all read "Ring of Bright Water". The last wild otters I saw were on a river in Brunei, but from the time I had dozens of polecats (fitch/ferrets) as pets, I can assure that they do curl up in a most appealing way and probably all mustelids do likewise.
I'm not sure I like Van Morrison (nothing against him personally!) or the phone and the microwave, because they date your poem. At the moment they date it as early 2000ish, and that temporarily makes your poem with it and modern, but in 20 years' time they will equally date it as old fashioned, a quaint period piece, when a little known musician was popular and people still actually used phones.
My niggles aside, I thought your poem was a great effort.
Yes, my instincts would tell me to drop the last three lines too. The remind me too much of an Elton John song, "your song" I think. No, the poem stands much better without it and it looks somehow more complete. Anyway, its up to you, this was deadly.