To be very childish and tell mil that sil is smoking when ........

[bogie]

Sil owes me £85 because she sold broken hair straighteners with my ebay account without my permission.

My reasons are:
Even though she owes me money she has decided that she is going to go on a £2000 cruise next month and tells me she's skint.
Sil took ds out and when I bumped into her she was sat with all her friends in a smoking shelter all smoking around ds.
Mil thinks the sun shines out of her arse but Mil Hates anyone smoking.
She cries (like a 4 year old throwing a tantrum) anytime I say have you got that money yet because I have debt collectors sending me letters all the time.
There is nothing I can do to pee her off apart from this because she is soo worried Mil will find out that every time dp and I go over there she won't let any of us be alone in a room with Mil in case we tell her.

I know this is really childish but she is pissing me off when she has all this money no rent, bills ect and can't pay her debts off even though we are going to have the debt collectors here very soon.

rather than tell MIL about the smoking (which won't get you anywhere) why don't you tell MIL about the money she owes you?

She knows about the money but she thinks Sil is an angel (she is the only person who thinks this) so she won't do anything because Sil raelly really cries when you try and say anything.
She cries her way out of anything.

To be honest, yes, I think you would be very childish to snitch on her for smoking.

It will piss her off, she probably won't talk to you, and you'll have a longer wait for your money.

Have it out with her, tell her firmly that you expect that money within a week, otherwise you'll take legal advice re the ebay incident.

I can see the temptation - seems this is your only weapon - but think shewillbeloved has the right, grown-up approach.

Or I suppose you could threaten SIL that you will tell MIL if she (SIL) doesn't pay up!

what age are you? This is the sort of thing I would have thought about doing when I was 12. If MIL knows about the smoking how will that help you get your money back? Won't it just make SIL more angry?

In her deepest heart, MIL probably knows that SIL smokes.

There's no such thing as an undiscovered secret smoker - it just smells too much.

I'd set it up so MIL catches SIL smoking as you don't get into sh!t at the same time.