PEM
'PEM' is an abbreviation for 'Post-ejaculation Mood'
The PEM describes a mood common to all males, experienced after ejaculation (after cumming) whether they have been masturbating, having sex, or were involved in sexual activities which caused them to ejaculate. Immediately after ejaculating males are overwhelmed by a feeling of disgust, laziness and regret; this is the PEM and can last from 10 seconds up to several hours, often relative to the volume of sperm ejaculation.

One very common symptom of being in a PEM is often quite a killer to the sex life, whilst in the 'PEM state' the person one has been involved in activities with, despite being as good looking as Cheryl Cole will appear to be more of a Susan Boyle whilst in a PEM.
After having the greatest tit-wank in his life, the young boy had to then face the resultant PEM that followed