When your watching porn on the internet and your connection is slow so your porn is jumpy and the sound is off beat with the action.
"man i was having a bat last night till i hit shag lag and i didnt know if i should keep going or stop"
by Cheyne Grainger June 13, 2007
The effects are similar to jet lag, but on this occasion the overwhelming tiredness is owing to a night full of bollock-draining sex. the following day they can't function properly in every sense of the word.
-Fancy coming with us for a kick about this morning?
-Fraid I can't, mate. I just don't have the energy.
-Suffering from Shag lag, eh?... Lucky bugger.
-Fraid I can't, mate. I just don't have the energy.
-Suffering from Shag lag, eh?... Lucky bugger.
by Bottom Face March 17, 2011
Fatigue following a rollicking sexual encounter.
Woman: Ready for another turn in the sack, honey?
Man: Would ya bleedin' leave me alone, I've terrible shag-lag after that!
Man: Would ya bleedin' leave me alone, I've terrible shag-lag after that!
by Kevin Scott (Yes! The one you know!) July 06, 2005