Talvin is getting serious!

Taylor Swift has been killing it at her sold-out 1989 tour stops in Los Angeles, but it appears her busy schedule hasn't put a damper on her relationship with her boyfriend, 31-year-old DJ/producer Calvin Harris. At the end of Taylor's show on Monday night, the 25-year-old "Style" singer was seen mouthing "I love you" in front of the catwalk, where Calvin just so happened to be standing.

WATCH: Taylor Swift and Calvin Harris Look So Smitten With One Another and We Can't Get Over It!

And before you start thinking the sweet gesture could have been dedicated to any random fan, Taylor liked this Tumblr post with the caption, "TAYLOR SAID I LOVE YOU TO CALVIN HARRIS AT THE END OF THE SHOW 08/24/15," pretty much confirming her big PDA.

For his part, Calvin looked just as smitten. The Scottish stud was spotted watching his girl from the stage on Monday, wearing a big grin on his face.

Calvin gushed about Taylor last month, when he told UK radio station, KIIS FM, that their relationship was "going absolutely fantastic."

"It's interesting because obviously there's different things written about it every day and even if we don't do anything publicly for a while, someone will make something up," he said. "For me it could be a lot worse, and I'd still be, like, insanely happy with her so I'm good with it."

He's also obviously protective over her, recently engaging in a Twitter spat with Zayn Malik over a perceived Taylor diss.

WATCH: Calvin Harris Cat-Sits for His Girl Taylor Swift

We're sure Calvin loved watching Taylor's show Monday night just like the rest of us, especially when she rocked out with Alanis Morissette to the Canadian singer's big 1995 hit, "You Oughta Know." Watch the epic moment in the video below:

Related Gallery

Taylor Swift's Boyfriends: The 'Lover' Look Back