Of no use to one, yet absolute bliss to two – Riddle

Solve the riddle:

Of no use to one
Yet absolute bliss to two.
The small boy gets it for nothing.
The young man has to lie for it.
The old man has to buy it.
The baby’s right,
The lover’s privilege,
The hypocrite’s mask.
To the young girl, faith;
To the married woman, hope;
To the old maid, charity.

What am I?

Below you will find a hint and the correct answer to the riddle.

Little hint:

Show Hint

Hint: K**s.

Right answer:

Show answer

Answer: Kiss.