You know – you've just had some good times, you're snuggling down, and think, "yes, I think I'll say a prayer now".
If you feel prompted to do such things, science might explain it. Especially if you're male.
According to new research, having sex could inspire some sort of divinity within us – a greater sense of purpose, perhaps.
Researchers at Duke University say that sex could inspire a belief – or an increased belief – in God and religion.
Sex releases something called oxytocin. It's also known as the "hug hormone" and "cuddle chemical", as it plays a crucial role in love and affection.
Oxytocin occurs naturally within us and is stimulated during sex, childbirth, and breastfeeding.
For a long time the chemical has been known to promote social bonding, trust, and even altruism.
Now, scientists at the North Carolina university in America say it could also incite spirituality in men too.
Research assistant, Professor Dr Patty Van Cappellen, says: "Spirituality and meditation have each been linked to health and well-being in previous research.
"We were interested in understanding biological factors that may enhance those spiritual experiences.
"Oxytocin appears to be part of the way our bodies support spiritual beliefs."
According to the study, spotted by the Bath Chronicle , women produce more oxytocin then men, but Duke University hasn't yet studied its affects on female godliness.
To test the chemical reaction in men, participants were given the hormone, and others received a placebo.
The men who got a dose of the "hug hormone" were more likely to say that spirituality was an important part of their lives. It had meaning.
They said so whether they'd previously noted that faith was a major aspect of their lives or not.
Those who took part also said they'd be more likely to see themselves as "interconnection with other people and living things", the study reports.
Oxytocin, it seems, sparked more positive emotions, such as awe, gratitude, hope, inspiration, love, and serenity. But it didn't affect everyone equally – those with a certain gene, called CD38 and which regulates its release in the brain, had a much more amplified response.
The study was published online in Social Cognitive and Affective Neuroscience .
Prof Van Cappellen adds that another study needs to be carried out with women as the chemical operates differently between genders.
"Oxytocin's effects on women's spirituality still needs to be investigated," she says.