The act of cuddling and other such public displays of affection (PDA) in an open area. Nesting is commonly done spontaneously with someone you don't particularly know very well.
Group nesting is called a Nest Fest.
This act can lead to Burrowing. Burrowing can lead to babies.
Joel - "Eli went off to nest with that girl again."
Sam- "What a nesting whore."
The sexiest family you will ever meet. When a bunch of them get together, they normally eat a lot then combine their awesomeness to make fire and/or explosions.
One step up from Nesting. This can include hardcore making out. This act is always done in public areas making everyone very uncomfortable.
Burrowing can lead to babies.