Nothing but net is the name of an entire category of some of the most intimate sexual positions. The criteria that a sexual position must meet in order to be considered part of the nothing but net category is rigidly defined as any position such that only genitals are touching.
Paying homage to its namesake, it is considered top form to make a "swish" sound at the outset of a nothing but net position. Neglecting to "swish" at adequate volume greatly increases risk of penile fracture.
For a couple containing a male that is not well endowed, it is likely that only limited exploration of the nothing but net category will take place due to anatomical restrictions only permitting a just the tip
(or JT squared) scenario.
Fucking in the airplane bathroom, we had to hold the walls so tight it was nothing but net.