I'd be interested to hear if this feeling usually proves to be correct. My mum is dating someone whom I distrust instinctively, despite him seeming nice. I can't put my finger on why, but my DP feels the same way. We both have quite good instincts when it comes to this sort of thing.
I recently found out that he has lied continuously about where his daughter went to university. Unfortunately my mum believes this lie and thinks the sun shines out of his arse.
Is this feeling usually reliable in your experience?