Calculate the number 2151

A man escapes from a prison where he had been kept for 15 years. As he runs away, he finds a house and breaks into it, looking for money and guns, but only finds a young couple in bed.
He orders the guy out of bed and ties him up in a chair. While tying the girl up to the bed, he gets on top of her, kisses her on the neck, then gets up, and goes to the bathroom.
While he's in there, the husband tells his wife, "Listen, this guy is an escaped prisoner, look at his clothes! He probably spent lots of time in jail, and hasn't seen a woman in years. I saw how he kissed your neck. If he wants sex, don't resist, don't complain, just do what he tells you, just give him satisfaction. This guy must be dangerous, if he gets angry, he'll kill us. Be strong, honey. I love you.", to which the wife responds,
"He was not kissing my neck. He was whispering in my ear. He told me he was gay, thought you were cute, and asked if we kept any Vaseline in the bathroom. Be strong, honey, I love you, too."