Finneas and Taylor Swift don’t have any ‘Bad Blood’ between them … but, he says his blood still runs cold whenever he thinks about an awkward encounter they had!

The 10-time Grammy winner sat down for an interview with The Guardian, published Saturday … and, he reflected on a mortifying moment between him and T-Swift when he attended her birthday party.

Finneas said Taylor thanked him for coming to her birthday party … and, he responded, “Thank you for coming!” — to her own party!

To be real … we’ve all been there — telling a server at a restaurant to enjoy their meal or an usher at a theater to also enjoy the show. It can get real darn awkward, but it seems Finneas is taking his blunder in stride.

BTW … this was a joint interview with Finneas and Ashe — a singer-songwriter he’s collaborating with — and, she’s got her own dose of awkward to add.

Ashe says she ran up to Margot Robbie at a costume party and told her people said they looked alike … total cringeworthy over-excited fan behavior Ashe hasn’t lived down either.

Of course, Margot’s well-known for being just as gregarious as Taylor … and, Ashe confirms she played the whole situation off well.