Oxytocin is a hormone produced by the human body for various reasons. It has both physical and psychological effects on the body. The two major roles of oxytocin is to help in child birth and release breastmilk for breastfeeding and in sperm movement. Oxytocin is also known as the love hormone as it is released when you feel an attachment with someone.
Sources:
https://www.health.harvard.edu/mind-and-mood/oxytocin-the-love-hormone
https://www.yourhormones.info/hormones/oxytocin/
https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3183515/
https://www.medicalnewstoday.com/articles/275795
https://www.healthline.com/health/love-hormone#dopamine-and-serotonin