I love you: A contraction of the sentence 'I love you' by converting the numerical digits into letters; 9 12 21 i.e. 9 = I, 12 = L and 21 = U. It is usually used to propose someone you secretly love, but which does not have bad effect.
"Hey Lucy, I wanna say you something, 91221!"
by ITeachThem October 09, 2013