S&P stands for "Sunshine & Pussy" - a glorious, joyous, happy state for a man to find himself in. It is when everything in a guy's life is "clicking" and going great - the weather is great, he's having a happy time partying and enjoying life, and - most importantly - he's on a big roll with the ladies and getting laid a lot by many different women. In fact, he just can't strike out - every woman he hits on, he successfully beds.
Marsh: How's your life, man? How's your summer?
Craigar: It's been awesome. S&P, man. All sunshine and pussy.