Sly Doggin 

to be cheatin on yo bitch

Tyler, are you sly doggin with that Ashlee hoe?

Sly Doggin by papadoggin December 6, 2010

Sly doggin it 

To go for a sneaky pint or a sneaky fag. To do something showing how much of a cute cunt you are. Drinking on the sly. Used only by a select group of skyboys in Connemara.

Are we sly doggin it down the pub tonight lads?

Sly doggin it by rubberbandit69 October 22, 2011

sly diggin' 

purposely talking about someone who's friends with you on facebook or follows you on twitter/instagram/tumblr.

friend one: yo, did you see that she was sly diggin' her ex on twitter
friend two: yeah, i really don't why she's still doing that. it's been a year after their break up

sly diggin' by Amelia Bottomly January 8, 2013