Not even the most unbelievable news from 2016.
A quick duck.com shows this is where the screenshot is from, though it appeared on other news sites and blogs too:
https://metro.co.uk/2016/12/22/fathe...marry-6339373/
Metro seems to specialize in grim and sordid stories about rape and murder on the streets of Britain (see the right sidebar), but this is a quite interesting article about how, before same-sex marriage was legalized in the US, Americans who wanted legal protections such as inheritance would 'adopt' their partner.
Far from a 'father and son' being allowed to marry, the article states:
"although same-sex marriage officially became legal in all 50 US states in 2015, Nino and Roland were told they couldn’t get married because they were legally father and son"
After failing to get the 'adoption' annulled they appealed, and finally a court agreed.
So by the time they were married they were not even technically/legally father and son, let alone biologically.
So the story is real but the headline isn't, because humans prefer fantasy to fact.