Worlds are colliding for a couple former Taylor Swift lovers … because Tom Hiddleston and Joe Alwyn crossed paths across the pond … with Tom watching Joe on stage.

Check out this photo floating around social media … you see Tom and Joe walking out of a production of “The Lady From The Sea” Sunday night at the Bridge Theatre in London.

Joe stars in the play … and it’s interesting to see him leaving right behind Tom … because Taylor was dating Tom back in 2016 when she dumped him for Joe.

So, on its face, it seems all these years later there are no hard feelings between the British actors.

Tom is now engaged to British actress and writer Zawe Ashton … they have a kid together and a second on the way.