That euphoric feeling directly after having an orgasm. After orgasm, both men and women release the chemicals oxytocin, prolactin, gamma amino butyric acid (GABA), and endorphins
that work to tell the body and mind to relax after sex.
We were just laying there enjoying the postcoital bliss and he said "I love you". And I said, "just enjoy the afterglow
and don't get all sappy".