US pop-star and gay-rights campaigner Lady Gaga has shared an on-screen kiss with Marge Simpson, in the latest episode of the longest running cartoon-sitcom on television.

The singer appeared as the most theatrical version of herself in the episode entitled ‘Lisa Goes Gaga,’ where she attempts to instil self-love in a dejected Lisa, voted as the least popular person in school.

When Marge bewails her inability to help Lisa, the cartoon version of Lady Gaga says, hesitantly, ‘Maybe this will help,’ and shares a passionate kiss with Lisa’s mum. The implication is that Marge feels excited by the kiss.

Neither Lady Gaga nor the Simpsons have been shy of their support for gay rights. Lady Gaga has declared that she is bisexual, and has claimed that it was men who seem most intimidated by it. The Simpsons have aired several pro-gay episodes, including one, ‘There’s Something About Marrying,’ where Springfield legalises equal marriage. The latter episode came with a disclaimer and a viewer discretion  from Fox saying it contained discussion about ‘same-sex relationships.’

One character, Smithers, has long been hinted to be in love with his boss, Mr Burns, the closest thing to a villain in the series. It also recently outed a seemingly macho-character, DuffMan, as being in a gay relationship.

The Gaga-based episode also featured the premiere of a song dedicated to her fans, called ‘Little Monsters.’