Girlfriend gone for long periods with driving instructor, should I be paranoid?

So this is a serious question and possibly a stupid one... my girlfriend found a driving instructor which is only £36 an hour which is the cheapest around. He keeps giving her a free hour every time they drive... which means he is bassically not making anything. He doesn't seem to do this with other students as far as I can tell. When I asked about it, my girlfriend just told me he's insane, funny and just said don't worry about it keep driving. I'm slightly paranoid in this situation, it's strange... should I say I'm uncomfortable with it? Or just leave it?
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+1 y
1h 30 this time for free and still going...
Girlfriend gone for long periods with driving instructor, should I be paranoid?
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