you could sense the seriousness in his voice, making you slightly nervous "Okay...what is it?

you look at him curiously, wondering what it is that he needs to tell you

You could sense the seriousness in his voice and you were a bit worried, but you held his hand tighter, trying to reassure him "Of course I came, you know I'm always here for you. What's going on? You're making me a bit nervous.