Bill Cosby says his attraction to the accuser in his pending sex-assault case began the day they met at Temple University.
Cosby describes their relationship as romantic. But her lawyers say he was only a mentor and trusted friend.
Their relationship will no doubt be explored in depth if a judge on Tuesday allows the 12-year-old case to trial.
Defence lawyers say the 78-year-old Cosby had a deal with authorities that he should testify in Andrea Constand's lawsuit because he would never be charged.
An ex-Montgomery County district attorney will give evidence for the defence on Tuesday.
The current prosecutor, Kevin Steele, says he has no evidence of any immunity deal.
The sex-assault charge stems from a 2004 encounter at Cosby's suburban Philadelphia home.