(to be) like a dog with two tails phrase informal
The phrase alludes to the belief that a dog wags its tail as a sign of pleasure or happiness.
To be very happy and excited about something
When my nephew received a new lego box, he was like a dog with two tails.
My friend has been like a dog with two tails since she got accepted to Harvard.
She will be like a dog with two tails if we hold a surprise birthday party for her.
To make someone feel more confident or happy, especially when they thought that they can't achieve what they want
Happy or cheerful; in a good mood
To smile broadly
People tend to like forbidden or illegal things just because they are forbidden or illegal.
He must have believed that stolen fruit is the sweetest, and he, therefore, cheated on his partner.