Sorry if this has been asked a bunch of times already but...How did they meet?

In the original canon, they were both studing theology in Venice at the same time. Vasco had been sent there by his parents, who had recently found out he's gay and hoped that proper strict education would straighten him up. Machete's former mentor had just became a bishop and no longer had time for keeping an apprentice, so he funded his further studies as a rare display of goodwill. Their classes overlapped a little bit so they knew each other by sight, but they mostly hang around in different circles. Vasco was well liked in his friend group which consisted of other sons of rich nobles, and Machete spent a lot of his free time voluntarily helping teachers and professors around the faculty or kept to himself. One of Vasco's buddies started picking on Machete and Vasco (as an overprotective 'can't have people feeling bad or sad around him' good boy he is) felt responsible and started following him around (mostly to soothe his own guilty conscience) and eventually they became friends.

Over time their relationship started to gain romantic tones and they ended up living together in a tiny rented attic room. I'm not sure how their break up played out exactly, but in the end Machete graduated and went on to be ordained as a priest (a goal he had trained for all his life), while Vasco dropped out and reluctantly returned to his parents, who swiftly forced him into a lavender marriage to cover up his sexuality. I can imagine them anquishing over the situation as the end loomed ever closer, trying to come up with a scenario where they could still secretly be together. Unfortunately at least one of them would have to throw away a promising future for a plan that could fail at any time. The price was too high and the risks were immense so they just had to allow the separation to happen. Some 10+ years later they meet again by random chance, Machete has advanced in his career rapidly and is now a cardinal secretary of state, and Vasco has followed his father's footsteps into politics and works as a Florentine ambassador. Since both of their jobs center around diplomacy and foreign relations, they end up working together frequently, which conveniently enables them to see each other off-the-clock as well. They resume where they left off.