Why, it's Mortimer!
5 seconds sound clip from the Mickey's rival (1936) movie soundboard.
You can hear this line at 00:01:17 in the DVD version of the movie.
Quote context
[...]
- Well, it if ain't my old sweetie Minnie Mouse.
- Mickey, I want you to meet Mortimer.
- Ta-da! Thank you, thank you, thank you.
[...]