English actor Harington and Scottish actress Leslie, 35, met while starring together in HBO’s sprawling fantasy series Game Of Thrones, which ended in 2019 after eight seasons.
The couple tied the knot in 2018 at Leslie’s ancestral home in Aberdeenshire before announcing the birth of their son in February 2021.
Appearing on The Tonight Show Starring Jimmy Fallon in the US, Harington said of his two-year-old son: “We think he might be quite smart. It’s surprising, seeing as we’re both actors, we’re not sure quite where that has come from.
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“He loves applause, every time he does something good we give him applause and we’re worrying that is kind of pushing him towards acting.
“We’re a bit like ‘You might be too smart for this, go save the world, we’re thick, we had no choice’.”
Harington, 36, added: “He’s about to get the shock of his life, which is he’s about to get a brother or sister. I’m terrified.
“With the first baby you’re walking on clouds and dancing through fields of daisies for nine months, well the man is anyway.
“But this time the reality check comes much sooner, you get practical real quick.
“I’m not sure he’s quite conceptually understood it yet. We’re trying to get him ready for it, we point at Rose’s tummy and we say ‘mummy’s baby’ and he points at his tummy and says ‘my baby’.”
Harington played Jon Snow in Game Of Thrones while Leslie played Ygritte.