ThkQ for the reminder, Jay.
Some believe they are on opposite ends of a spectrum.
It has scant mentions in mainstream American dialog, other than that time in 2013 when Amanda Bynes by a cop, according to her own of the incident.
Like Jay Dee said, there is a close cross-over between pain and pleasure.
I suggest coconut oil, but you can use your own favorite lube, or warm the wife up by some other means until she self-lubricates.
I think that is one of the biggest factors for us.