Lofn

In Norse Mythology, Lofn as a Goddess concerned with sparking passionate love. She had permission from Odin and Frigg to do so even for those who were forbidden to marry.

Source: Nicole Cherry, A list of Norse Beings, originally at http://www.ugcs.caltech.edu/~cherryne.
Copy still available at https://www.angelfire.com/wy/wyrd/list.html

Note the similarity with Roman and Greek mythology, which also had two goddesses of love: Venus / Aphrodite for passionate love, and Juno / Hera for married love.