Crossbench senator Ricky Muir has revealed he switched his position on same-sex marriage after a fight with his wife in which he said he would disown his son if he was gay.

The Motoring Enthusiast Party senator announced his support for same-sex marriage earlier this year, linking the issue to rural mental health.

"I did have very opposing views to what I have now, but that's because it's 'monkey see, monkey do'," Senator Muir told Annabel Crabb in an episode of Kitchen Cabinet to air on the ABC on Wednesday.