She took Sean???s advice ???because he???s my son and I don???t want to be sort of argument, you know???? Yoko explains, though she feared it might be too out-there. ???I didn???t know if I should go really rock and just go on in my underwear or something,??? she says. ???She doesn???t mean underwear,??? Sean corrects. ???She means like an undershirt.??? (She wore Alexander McQueen.)