1. L’amore non è bello, se non è litigarello
There is no equivalent in English, although searching, I came across a quote by Shakespeare that sums up the meaning of the Italian provarb above.
“The course of true love never runs smooth.”
When do Italians say “l’amore non è bello se non è litigarello?”
This Italian proverb pretends to ease the tension after a little quarrel by objecting that a relationship can’t always be “bella‘(or healthy) without a small fight from time to time. Of course, the hardest times make your relationship stronger. The adjective litigarello (originating from the verb litigare) is not used in any other expressions, but this one.
2. Chi s’assomiglia si piglia
Literally, those who are alike end up with each other.
The proverb originates from the Tuscany dialect and means that those who have similar features (both in their bodies and their characters) are attracted to each other.
3. Sfortunato al gioco fortunato in amore
Literally: unlucky at cards, lucky in love.
This Italian saying is often used to ease the pain of somebody who is losing while playing a game, usually playing cards.
4. Il primo amore non si scorda mai
English: You never forget your first love. The proverb explains itself.
5. Al cuore non si comanda
English: Love is blind, or you can’t rule the heart. A person who is in love might not see the faults in his/her partner the way others might see them. It sounds pretty malicious, but I have heard it a few times.