Hugh Hefner doesn't believe monogamy is "natural".
The 85-year-old media mogul - who is famed for dating multiple women at the same time - is preparing to marry Crystal Harris later this month and insists he is a good husband who intends to remain faithful, though he feels it could be difficult.
He said: "I'm totally capable of being a good husband. I can be devoted, sensitive. Faithful? Yes. Absolutely.
"I do think that monogamy is possible. I just don't think it's the natural way of things."
The Playboy founder - who has been married twice before - admits there is a "student-teacher" aspect to his relationship with 24-year-old Crystal but can't imagine spending the rest of his life with anyone else.
He said: "I wasn't planning on getting married again but I can't imagine meeting anyone I'd get on better with. People make so much of the age gap, but we have a lot in common.
"Yes, there's a certain student-teacher quality to our relationship, but surrounding myself with younger people helps keep me younger."
Hugh also believes his reserved upbringing is responsible for his multiple relationships in later life.
He said: "I haven't had therapy but yes, I do think it's possible that a lack of love in the home transformed itself into a desire for romantic love later on.
"I was raised in a house where there weren't a lot of hugs and my brother and I were both very aware of that."