1. When two males rub their penises together
2. When males flirt and complement one another, particularly management in an office corridor
1. Gay men getting home and nashing after meeting in a bar.
2. "I like that report that you put together for the GM", male 1. "I thought it was ok but I can never produce one as good as yours", male 2. This tyype of "flirting" indicates that two otherwise straight men would like to be nashing with one another in the copy room.
Then a lame joke ensues and they talk about the hobby that they pretend to have in common (e.g. yachting)