I love Stan Tatkin. He is clear and easy to follow. This video is a great introduction for understanding how we are hard wired and the effect on relationships. Stan’s book Wired for Love goes into more detail and well worth the read.
There are many wonderful poets that have captured what love is over time such as Rumi, and here is one from Kahlil Gibran ….
A wonderful talk by Ester Perel on infidelity.