Silver and Espio first met in Sonic Rivals 2 when Espio got a meeting mission to find evidence that Silver was behind the kidnapping of Chao. Espio treated Silver as an enemy at first, but Espio started to doubt the mission as Silver did not seem like a bad guy. When Espio found out Silver was trying to save the world, he followed his instict and joined Silver in his mission. The two went on an adventure together and built a good relationship during it.
As the two were about to stop Eggman Nega from feeding Chao to the Ifrit, Espio noticed Silver was exhausted. Espio went to collect some rings to give him more energy, and even fought Sonic over them.
When Espio and Silver found out Eggman Nega already had enough Chao for the Ifrit, the two teamed up to save them, although Espio was slowed down by Rouge. After their mission was finished, the two thanked each other and Silver left.
The two have reappeared together in some games, although no notable interactions are shown. In Sonic Generations, both cheered Sonic on during his battle against the Time Eater and later celebrated Sonic's birthday. In Sonic Forces, the two were members of the Resistance.
Espilver has some support following their appearance as a duo in Sonic Rivals 2. It is one of the more popular slash ships in the fandom, and one of the most popular ships for Espio.