PITTSBURGH >> The sex assault case against Bill Cosby turns on serious questions about his actions with women behind closed doors, but the comedian and others unexpectedly fell into laughter Wednesday during questioning of one potential juror.

When asked why he was claiming hardship, an older man responded by asking the judge if he’d heard of ulcerative colitis. Playing along, the judge asked the juror to describe the condition.

“It doesn’t act up all the time, but if I deviate from my home diet, usually in about an hour or two, I’m in a place where I need to use the facilities right now,” he told the judge. The remark prompted Cosby to begin laughing to the point of tears.

Cosby, the judge and lawyers chuckled as the man continued answering questions.

The grandfather also got big laughs and applause from the comedian-turned-defendant with this line: “I always tell everyone I’ve only been married a short time — 45 years. People have gotten out of jail sooner than that.”

The judge asked if there was any other reason the man couldn’t serve as a juror beyond his medical condition. At that point, he volunteered that his 21-year-old grandson already had sprung for the two of them to go to Las Vegas next month — which would conflict with the trial date.

The man wasn’t selected.

Cosby, once known as America’s Dad for his role in his long-running sitcom, is charged with drugging and molesting a woman at his home near Philadelphia in 2004. He has called the encounter consensual. Dozens of other women have made similar accusations against the 79-year-old entertainer, but the judge is allowing only one of them to testify.