Phrase which justifies unexplainable, illegal, degrading, disrepectful, and morally objectionable behavior, while usually under the influence of one or multiple control substances with a BAC excessivly exceeding the legal limit; causing physical, mental and personal property damage far exceeding personal financial responsibilities, with lack of care to the general public safety or ones self. Examples of justifying behavior include "shitting in a strangers dryer" which can be explained, justified, and resolved simply with "Sorry I Party". Acts covered under the blanket of "Sorry I Party" are usually uncomprehendable to the normal functioning human brain.
Dude, you snorted a line of urine off asphalt pavement last night then proceeded to snort a line of coke off a homeless mans boner. Well "Sorry I Party!"