The loved-up couple, who have been dating for four months, strolled arm-in-arm through the streets of Paris and it appears that Song has had an impact on the former child actor's health.
It was back in 2012 that Culkin made headlines for his incredibly slender frame. Now, the actor has ditched his long hair and messy beard for a somewhat smarter look - even wearing a suit to dinner!
The couple were also spotted with Culkin's goddaughter, Paris Jackson, who was seen earlier this week in a series of bizarre events on the streets of Paris. The daughter of the late King of Pop was seen sitting on the streets of Paris late at night smoking a cigarette, as well as scaling lamp posts.
You can see the bizarre images here.
Macaulay Culkin's new movie, Changeland, is due for release in 2018 and it also stars his new girlfriend Brenda.
You can see the official images of Culkin out to dinner in Paris here.