If HE or SHE comes from Mainland of China, then you should say "WO AI NI". "WO AI NI" is a Chinese Mandarin / Han Yu.
If HE or SHE use Hokkien (Hokkian) AND from Indonesia (mostly from Medan city) or Singapore or Malay, then I suggest you to say "WA AI LO".
WA = I / me
AI = love / want (to)
LO = you
Some speaking of Hokkien ( Medan, Indonesia version ) :
Wa ai lo.
Means : I love you / I want you.
Wa ai khi.
Means : I want to go
Lo hokkien esai ?
Means : Can you speak Hokkien ?
Lo ciak liao boi ? Wa ciak hamik.
Means : Have you eat(breakfast/lunch/dinner) ? I'm already eat(breakfast/lunch/dinner).
Ce / No / Sa / Si / Nggo / Lak / Jit / Pek / Kao / Cap
Means : 1 / 2 / 3 / 4 / 5 / 6 / 7 / 8 / 9 / 10
PS: Sometimes I use this for conversations with my friends (from Medan, Indonesia).
Hope this help ^o^