In asking my friend (and neighbour) for the tenner back she borrowed 4 weeks ago?

[TurkeyLurkyWithAllTheTrimmings]

I have known her for 7 years, she is a neighbour (and friend). We were out one night about 4 weeks ago and she borrowed £10 from me as she had forgot her purse.

She hasn't paid it back to me yet, she mentioned that fact that she owed it me about 2 weeks ago but I think has forgotten since.

I'd say we're about the same financially, I am not hard up but not rich either and won't miss the tenner but rather ridiculously it is niggling me that she hasn't paid it back (she is not hard up I don't think - about the same as me). Am I being a tight arse?

Shall I just let it go? It'd be excruciatingly embarrassing if I asked her for it back now wouldn't it?

My (short of money) nanna had a good excuse lined up when asked to lend:

She'd say, "No, I'm sorry but I only have one £10 note for borrowing, and it's out on loan at the moment".