“Trust me on this.”
Trust me on this. asks the listener to believe the speaker on this particular point. Here Frank insists that he really cannot sing.
A1-49 / CEFR A1 / EPISODE 49
Trying something difficult with a friend
SceneIn a karaoke room in their usual town.

WORDS & CONTEXT
Trust me on this. asks the listener to believe the speaker on this particular point. Here Frank insists that he really cannot sing.
Twinkle, twinkle, little star is a very well-known English-language children's song, with the same melody as the Japanese “Kirakira-boshi.” Twinkle means to shine with small flashes of light, echoing Tina's origins among the stars.
See? is used to point something out to someone, like "See, I told you!" Frank said I cannot sing. at first, but he has just sung, so Tina replies, "You can sing!"
It refers to Frank's singing voice. When Frank calls his voice terrible, Tina answers that she likes it. One more song means another song. She asked for just one song, and right after he sings it she asks for another. That is the punchline.