Not my experience, but my grandma (86 years old) told me about this woman from her area who was supposedly together with her dad (as in, this woman’s own dad) for decades. My grandma is a strong believer that this rumor is indeed true, because apparently it was indirectly confirmed by the woman’s ex-husband and the dad’s ex-wife multiple times. Both of them are dead now, the dad died in 2013 and the woman in 2016. Truly insane. Very curious about your own communities’ scandalous rumors.