How I Met Your Mother Episode 4.05 Shelter Island

When Stella's sister's rustic wedding falls apart, Ted and Stella step in to get married with only a few days' notice. Despite the short notice, Robin catches a flight back from Tokyo. But when Stella finds out Ted invited Robin, the divisive issue of whether an ex should even attend a wedding threatens to overshadow everything. In an effort to make Stella okay with Robin attending, Ted winds up inviting Stella's ex, Tony, and in the end learns the hard way why it's not a good idea to invite an ex to your wedding.