The young Belgian stepped out in Europe's premier club competition against Manchester United at Old Trafford on Tuesday for the first time in the UK.
Lukaku took to Twitter to give a shoutout to his cousin who played the full 90 minutes in Brugge's 3-1 loss to the Red Devils.
Feels good to see my cousin @BBolingoli play his first champions league game in england #ProudMomentForTheFamily#EspecialyYouGrandpa
— R.Lukaku Bolingoli10 (@RomeluLukaku9) August 18, 2015
20-year-old left-back Bolingoli-Mbomo has been with Brugge since 2010 when he arrived at the Belgian club's youth academy as a teenager.