When out on the pop, always, always, always walk around the joint finding all the ugly birds and, whilst still relatively together, say one of the following things:
1. Have you just farted?
2. Been chasing parked JCBs?
3. If you look like your mother, I think I may have s-----d her a few weeks ago
4. I always swamp after sex
That way, no matter how much you may try later, they won't sleep with you.
I've never done the walk of shame since!
s4m