Other than "Gay and Proud" T-shirts or Rainbow Attire, how can you tell?
And even then, do you know?
I mean, you may be right.
But I've never seen anybody "visibly gay" at Mass. Girls do hug and kiss at the Peace, but that's just girls being girls and their mamas didn't tell them that's not for Mass.
So. ??
Holding hands, kissing, the way they both pay attention to their foster kid.