Short answers, pulled from the story.
Russia introduced a statutory ban on same-sex marriages in 1995 through Article 1(3) of the Family Code. This law explicitly forbids same-sex marriages and was upheld by the Constitutional Court of Russia in a 2006 judgement.
Slava Mogutin and his partner Robert Filippini applied to marry at a registry office in Moscow in April 1994 but were denied because the director could not perform the marriage by law. The couple became targets of highly publicized criminal cases carrying potential prison sentences of up to seven years' imprisonment before fleeing to file for political asylum in the United States.
On the 7th of July 2021, the European Court of Human Rights ruled that Russia had an obligation to ensure respect for applicants' private and family life by providing a legal framework allowing them to have their relationships acknowledged. Russia ceased to be a party to the ECHR on the 16th of September 2022 after being expelled from the Council of Europe.
Following the 2020 constitutional referendum, Article 72 of the Russian Constitution defines marriage as the voluntary union between a man and a woman. This amendment explicitly bans same-sex marriage and was passed unanimously in the State Duma in March 2020.
Pavel Stotsko and Evgenii Voitsekhovskii married at Copenhagen City Hall in Denmark on the 4th of January 2018. They were indirectly acknowledged by Russian authorities as married on their passports until the couple fled Russia citing threats to their liberty and security, leading to a court case accusing them of intentional damage to official documents.
A June 2019 Public Opinion Foundation survey found that 7% of respondents supported same-sex marriage while 85% were opposed. Support for same-sex marriage declined from 18% in 1995 to just 5% in 2013 before reaching this 7% figure in 2019.