口ではああいってたけど本心かしらねアレはの英語

What he say, is opposite to what he means

He talks like that, but it is only talk.

He never opens his mouth without putting his foot in it.

He talks as if he knew everything.

What we say and what we mean are often quite different.

You talk as if you knew everything.

pretexts are never wanting

Don't talk with your mouth full.

to give a loose to one's tongue

His story must be taken with a grain of salt―taken with some grains of allowance.

He talks like that, but it is all talk.

silly phrases fell from her mouth

I can not express what I mean―put my thoughts in words.

He has a sharp tongue.

He says one thing and means another

He said so, but, to tell the truth, he was unwilling to do it from the first.

He can not open his mouth without putting his foot in it.

He has a smooth tongue.

He says one thing and means another.

He mutters something.

the act of saying whatever comes into one's head

unspeakable joy

Heaven will punish you for saying such a thing.

The statement is too sweeping.

If you do such a thing, I shall lose my position

Easier said than done.

He says one thing and means another

Ouch! I burned my mouth.

Don't speak with your mouth full!

the physical characteristic of having a harelip