What does this Jens Lekman lyric mean - "You're a drop of blood in my glass of milk"?

Question

You can hear a live version of the song here, if it helps: http://www.youtube.com/watch?v=qNvePvMJYqs

The entire lyrics are here: http://www.songmeanings.net/lyric.php?lid=3530822107858681221

It's a sweet little song about getting his hair cut by a former Iraqi woman in her apartment. In the song, he says:

"Your hands are soft
your hands are soft just like silk
You're a drop of blood
You're a drop of blood in my glass of milk "

I'm trying to figure out what he means by 'a drop of blood in my glass of milk' - what this is meant to symbolize or represent.

What do you think it means?

Answer 1

Something that doesn't belong, something that ruins everything