Possible metaphor
I think it's a metaphor for sex there's some clues but i aint conected them all yet.
Luxembourg- The smallest country in Europe is the most popular guy - Size doesn't matter
What the pulch looks like - obvious.
The trick is in the timing - Ejaculation.
Maybe it's also about how in a relationship it's good up untill after the sex, in which intrest is lost.....i don't know.