I’m on a conference call with Ryan O’Neal and Ali MacGraw. He’s in Malibu, and she’s in Santa Fe. He’s already serenaded me with a raspy rendition of George M. Cohan’s tune “Harrigan,” and he’s terribly sorry that he got my name wrong. The two actors will be in Boston this week starring in A.R. Gurney’s “Love Letters” at the Shubert Theatre, and O’Neal has one burning question.