Jimellow

I suspect paying for the lift ticket was the payment/reward for you picking up his friend. It also skirts the issue of whether you are being used, as you're less likely to bring it up if you're receiving something for your efforts.

As someone that "helps" others quite often, I'd say the decision is up to you. To call him/her on it will likely result in you having to be unpleasantly honest, but it could be beneficial if it sets things straight without upsetting them to the point of not wanting to be friends anymore.

It can be very enlightening to take a step back and view relationships from the standpoint of who generally is giving, and who is taking. It's also a nice way of tightening up who are genuine friends and who are just acquaintances that enjoy the benefits that come with being in a relationship with you.

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Desperation is no excuse for lowering one's standards.