xoi
Means "hugs, kisses and sex"
"x" = kiss
"o" = hug
"i" = sex    (similar to "sex u later")

It is the normal "hugs and kisses", with a twist.
Therefore a different version of the well known xoxo, xo, xxx, and so on..

xoi is usually used when saying goodbye to show the amount of love or passion one has for another person.

This term should only be used between best friends or between a couple

Can also be written as:
iii (repeat as many times as u like)
xoixoi (repeat as many times as u like)

(1)
gtg bestie
mwa!
xoi

(2)
I LOVE U
xxxxxxxxxxxxxxxxxxx
oooooooooooooooo
iiiiiiiiiiii

(3)
i want u
iiiiiiiiiiiii