In аnticipаtiоn fоr а medical schоol swimming party, a 60-year-old male professor squeezes into last year's bikini bathing suit despite gaining 25 lbs. over the winter. Following a day of "impressing" his students and colleagues, he notices numbness, tingling, and a burning sensation in the lateral aspect of his left upper thigh. His symptoms are exacerbated by applying pressure near the left anterior superior iliac spine. What nerve is most likely affected?