Smile, a little
or bray, cachinnate,
cackle, chortle, chuckle, or giggle.

You can have a reward smile
or, perhaps an affiliative smile
could be a dominance smile
even the lying smile
Could be the wistful smile
Conceivably the polite smile
Possibly the flirtatious smile
or, perchance the embarrassed smile.

Does not matter!

As long as you smile with your untainted heart,
that's matters the most.

Therefore, smile
By reflecting your unsullied heart.