The nip of her teeth tempts him to stop talking in favor of other activities but... the words of River's visiting sister float into his mind then.

"When you say your people, do you mean your birth family, River? Is that a tradition they have?" He's not too worried about the obstacle. It's no worse than a necktie, and with neckties, he has to be careful about stains.

"The closest equivalent I have is exchanging wedding rings."