first love

noun3

1. •
   One's first experience of the feeling of romantic love.

   • Could this be love?—pure, first love for a shopkeeper's daughter. — 1852
2. •
   The first person to be the object of one's romantic affection.

   • [A]fter I made the personal acquaintance of Mr. Thrall's chef, Anatole, I found my affections dividing themselves between him and his lordship's man Robert, my first love. — 1907
3. •
   The thing, place, or activity of which one is fondest; one's most fundamental interest or attachment.

   • He had a very strong and faithful attachment for places: Chatham, I think, being his first love in this respect. — 1897