A second look may be flattering; after that, things go downhill: first to staring, then to ogling, finally to frankly leering.

Mennad's life started to go downhill.

When things go downhill and light at the end of the tunnel isn't visible, then it is time to strategically develop developmental plans.

The weather is supposed to go downhill starting this afternoon.

And it doesn't take long to go downhill.