What are family members for, if not to interrupt Saturday Night Live hosts’ monologues — and, in the case of Carey Mulligan’s husband, Marcus Mumford — strum a few chords of their hit late-2000s single? Mulligan made her SNL debut last night as the self-proclaimed “first English person to ever host this show,” and barely got through her requisite Michelle Williams jokes before Mumford (frontman of Mumford & Sons) interrupted, explaining that he left their kids at home with “the Sons.” He breaks out his guitar, despite Mulligan’s pleas not to be “the guy who takes his acoustic guitar out at a party,” (“people love that guy!” Mumford counters). Mulligan eventually relents and lets Mumford onstage to send the audience off to commercial, and the whole thing, while a little predictable, is very sweet and very British.