No – Smithy didn't say yes to Nessa. In fact, he didn't say anything at all…
Instead, Smithy agreed to marry Sonia – that's right, his girlfriend (now fiancée) who was last seen in the 2019 Christmas special, played by Laura Aikman.
"I called Ruth and was like, 'I wonder if we could trick everybody into thinking that, for the first six or seven minutes, that they're just going to watch a wedding that's between Nessa and Smithy'," said co-creator, James Corden.