Humans release small amounts of oxytocin when we show affection to our pets, and visa versa.

Doctors have found that mutual gazing between humans and their dogs increases the owners’ oxytocin levels. This helps decrease anxiety and arousal levels, and slow the heart rate. The positive interaction between humans and dogs via mutual gazing may reduce stress activity for each other (Washington Post, 2016)

Humans release large amounts of oxytocin during intercourse. 

Oxytocin makes us instantly bond with those that we have intimate physical relations with. But be warned, this "love" is not all it takes to have a healthy and long lasting relationship.

According to one statistician, only 2% of marriages are to high school sweethearts, and only 54% of high-school sweetheart marriages last 10+ years. Don't fret if your first relationship doesn't work out. (Gaille, 2021)

When a mother gives birth, they release huge amounts of oxytocin.

A study on mothers found that low levels of blood serum oxytocin was linked to postpartum depression and early breastfeeding cessation.

"The hormone causes uterine contractions during labor and helps shrink the uterus after delivery. When an infant suckles at his or her mother's breast, the stimulation causes a release of oxytocin, which, in turn, orders the body to "let down" milk for the baby to drink. 

Dads who got a boost of oxytocin via a nasal spray played more closely with their 5-month-old babies than dads who didn't get the hormone zap, a 2012 study found." (LiveScience, 2015)