"I'll tell you of more, and lie...so you will come."Catullus
Why? Isn't the truth enough?
Here we must consider authenticity.
One is not authentic but is looking for companionship or a relationship. So one is starving and refusing food. It makes just as much sense.
There are many things left unsaid here, many issues that Catullus in spinning his web for his visitor perhaps didn't consider. Those who kiss the Blarney Stone must first put themselves in a very precarious position. Is Catullus terrified that the trust he placed in his companion's hands will not be vindicated? There's hope here, swinging from the lie, and faith.
If love is strong enough then Catullus was not only right but very clever. It comes down to discernment at the end. Not desperate but a game.