Paul Mescal On Date With Gracie Abrams in London

We have a possible new couple alert from across the pond ... because we just got photos of Paul Mescal on a date with Gracie Abrams. Check it out ... the Irish star and the "us." singer are sitting at a tiny table together inside a packed restaurant for what appears to be a dinner date. Folks who were there say Paul and Gracie broke bread at BRAT Restaurant in London, where they ordered a bunch of small sharing…