First

Theres a first for everything.
A first step. A first word. A first sentence. A first birthday. A first friend. A first best friend. A first hug. A first kiss. A first for holding hands. A first boyfriend. A first love.
But you can only fall in love once, because you never fall back out, because you are In LOVE with them. You two go through everything together and grow old together. Thats what being in love is, so you cant fall in love more then once.