I don't, but my wife does.
She normally sings "Lipstick on my collar", "Hey big spender", "These boots are made for walkin'" and a couple more. As long as she's not too drunk she's pretty good.
Main place for her performances is The Round-Up Saloon in Carvoeiro, The Algarve. Usually gets up with the bar owner, the infamous Big Will, a giant of a dutchman (ex world strongman competitor). Plus the K team in Round Up are brill singers as well, so they usually step in early in the evening to get it going.
She tried K in Condor last summer, but the DJ keeps playing records in between instead of letting the K to get going. And it's not led by a Karaoke DJ so wasn't impressed with Condor for K. We'll have to try Thomas Bay this June.
I must admit i used to hate K nights but a couple of times/week on holiday is good fun.