trail of happiness
The dark, vertical hairline found on the torso of males, but sometimes females, below the belly button that leads straight to the fun bits.
Homygawd, this beach hottie's board shorts were so low that I got a look at his trail of happiness.
trail to happiness
The typically narrow strip of hair on a male that leads from the naval (belly button) down toward the pubic region.
When I take off my shirt, everyone can see my trail to happiness.