Whip it good - and you'll reap the romantic rewards.
Couples who regularly engage in S&M practices like spanking, bondage or other semi-violent fetish fantasies end up bound closer together and stress-free, a pair of new studies shows.
Men and women who participated in the studies, published together this week in the Archives of Sexual Behavior Journal, showed increased levels of testosterone - and pleasure - when their S&M experiences went well.
Those who reported good S&M experiences also showed a increase in cortisol, indicating a corresponding drop in stress levels and anxiety.
Of course, couples who didn't enjoy the S&M showed increased levels of stress and detachment from their significant others, according to the studies, which were conducted by researchers at Northern Illinois University and the University of Pisa in Italy.
But giving each other a sexy spanking did help many coupled-up partners feel closer to one another - those who were happy with their S&M time reported they experienced a tighter emotional bond.
Couples who spend more time together - whether it's leather-clad in the bedroom or walking along the beach - are likely to become closer, experts say.
"It doesn't have to be tying up your partner or placing clamps on their nipples, it could be something as simple as cooking a meal together or even doing the housework as a duo," Richard Wiseman, a psychologist at the University of Hertfordshire in Hatfield, UK, told New Scientist magazine.