Twice recently friends have borrowed money for the train from me. Once the person actively asked me to put her tickets on my card and she would pay me back (4 weeks ago and £10) and the other time a different friend forgot her wallet (2 weeks ago and £20). I am pretty non confrontational and I really don't know how to ask for the money back without it sounding rude and petty but at the same time I don't want to be sat £30 down (We are a 1 income family). If I borrow money from someone I try to pay them back straight away (and tbh I avoid borrowing as I feel guilty). Is it usual for people to borrow and then never mention it again?? Any suggestions of polite ways to ask (I have already asked one friend once). I really don't want to come across as stingy but it puts me off lending to people :( It feels rude to just bring up in conversation though...'oi you own me money', how do other people approach this?