In Spanish we use this expression abuse of your trust usually in formal writing to apologise in advance when we want to ask for something that one wouldn't do if wasn't because our trust.
Example.
Sorry for making abuse of your trust but I wonder you'd do a favour. Can I borrow your car for the weekend?
How would you express this in English?
Thanks.
Best Answer
The phrase makes sense in English but the meaning it conveys is far too severe for the context you give. An "abuse of trust" in English would be a very serious matter and even describes some illegal acts - for example, the definition "abuse of a position of trust" is used in British law to describe sexual activity between a teacher and student, or a caregiver and care-recipient. Not quite the same thing as asking to borrow someone's car.
I think the equivalent expression you are looking for is:
Preceding a polite request this normally implies that you are aware you are asking for slightly more than would normally be expected.
Another alternative may be to say:
This is another way that some may soften a request by apologising in advance for presuming that it is possible.