Is this correct usage of the word "spoil"?

Is the following statement appropriate?

A concerned expression starts to slowly spoil his looks.

I am trying to say that a person's expression saddens within a minute or two while pondering over something, but not instantly as would be the case when caused by shock

Solution 1:

Yes, that is perfectly good usage. 'to spoil' can just mean 'to ruin'.

"The drunk clown spoiled the birthday party for everyone."

I'd rather question your usage of 'slowly'; do you mean in the course of a conversation, he developed a "concerned expression" and that made him look bad, or is it over a lifetime?

Also 'start' and 'slowly' are a bit at odds for 'spoiling'; a runner can start slowly but pick up speed, but 'to spoil', it sounds a little strange there.

Solution 2:

It's an unusual usage, to say the least. Spoil normally applies to processes that take quite a bit longer than a change of facial expression, even though in this case the sentence explicitly says the change is happening slowly.

It's common, for example, to find reference to things like smoking, long-term drinking, smallpox, wearing spectacles, etc. "spoiling [her] looks".

Having said that, OP's example might turn up as a somewhat contrived metaphorical usage in "flowery" fiction or poetry, but for me at least it wouldn't hit the spot. Except if it were in the unusual context of "over a lifetime" as suggested by @Mitch (some crushingly depressing circumstance lasting for years, perhaps), which I might think of as inventive and striking usage.

LATER: I know this isn't writers.se, but I was never all that happy with "looks" being degraded by a temporary change in expression in the first place. How about A concerned expression slowly cast over his face?