The meaning of the Idioms: tongue-tied, mate, on the sly

Hi! My friends! The meaning of these idioms is as follows + Russian Translation:

Tongue-tied  — без дара речи (как временное состояние, например, из-за волнения)

When people clap the girls get tongue-tied.

I feel that fame won’t do them any good.

To mate smo with — свести кого-то с кем-то

It’s obvious! Parents want to mate you with that man.

He’s wealthy and handsome / rolling in it

To be on the sly — ВТИХАРЯ, ТАЙКОМ

I bought the pink dress on the sly.

The mouse stole the cheese on the sly.