In a new video, lasting less than a minute, the 19-year-old boy said he has now “repented”.
He also vowed he would no longer use social media in a way that could violate general decency, according to a translation by Al Arabiya.
The humorous videos show Abu Sin – whose nickname translates as “toothless” – and Christina, 21, chatting to each other from their homes in Saudi Arabia and California.
They battle language differences and jokingly declare their love for each other.
In another video, Abu Sin dons a traditional Saudi headdress and sings a traditional song to Christina, before asking her to marry him.
Authorities said the boy was 19-years-old, though he looks considerably younger in the footage.
In one video, he tells Christina he is 20, before she replies sceptically: “But you’re only 13.”