So whenever i'm out and i go back on facebook (decription)

Whenever i go out then i come back , i go on facebook and my close friends my fiance is on the list and it shows that he liked a bunch of two of his ex's pictures.... What do i do? Does he still have feelings for them? But i dont want to confront him about it because no matter what he gets over worked because he's always stressed from work .......... :/