This is probably going to sound a bit petty to some, but there is a LOT of background, but would require a novel to even begin to explain it all, so without wanting to drip feed, I will keep the background brief.
My DM died last year, she was a Narcassist, but in part this was illness induced & it's only since losing her I'm realising just how much my DB used her illness to manipulate her & how much he hates me & has been the root cause of a lot of bad feeling towards me - he's 2 faced to the max & also I realise a Narc, one I now realise, who for some bizarre reason seems very jealous of me & loves to poison everyone against me & he even started in my DD
Lots & lots of layers to it as there always is with this sort of family dynamics & my DF though not always so bad as regards cutting me out for years on end, is also pretty toxic when he wants to be.
I live a long way away, that's worked best for me for obvious reasons.
Made peace with my DM before losing her & spent those final weeks at her bedside fighting for better care for her - neither DF, nor DB coped well & that in itself caused trouble - but heell, what doesn't in our family - thankfully I'm wise to it & it has made me tough I suppose.
I did a lot for DB after DMs death, in her memory & also as he is my little DB & he was living in a mess & I just fell into helping him sort himself out, but wanted to, in the hope it would finally get him in the right track - he made a huge deal out of how grateful he was.
Then suddenly after I had to change my travel plans for visiting again as I was too ill to travel on the day arranged - he exploded on me - a whole novel of an email after I put the phone down on him ranting at me, calling me & DD all the names under the sun, gloating over how he "made sure DM saw me as the crap DD, rubbish DM & awful person I always was & how he would look forward to making sure DF saw the same & how DD (only 10 at the time
) was as bad as me. Lots of strange incident over the years suddenly explained - all where I was trying to help, but it was twisted into something else & I suddenly found myself accused if all sorts if things that couldn't be further from the truth - I could go on & on
Since DBs toxic rant at me alongside stalking DD around the internet in order to show up what a rubbish DM I am & followed up by him trying to hack into my internet accounts - I suspect to retrieve the email rant & other emails where he lays himself bare & incriminates himself badly as far as drugs go etc - I've backed off.
DF insists he sees through DB & can't be manipulated by him - but DF is elderly, has health problems & though no saint himself, is obviously vulnerable to DBs subtle toxic whisperings against my family.
We occasionally see DB as DF organises family lunches in a cafe & I go along with it & I am polite for DFs sake, but until I get a heartfelt apology, then I cannot forgive DB for all he has done - DF barely knows the half if it, but knows enough & comments himself on how 2 faced DB is.
Okay that's just a teeny amount of the background
Current situation is...
Wealthy DF insisted on giving me money towards train fare for DD & my visit last week - this time round we actually needed it, as DH has just finished work & currently no income at all as my o?n health & DDs has been bad, plus other battles taking over my life meaning I have been unable to work for some time myself, so the trip was something we couldn't afford, Butkus to DD being in hospital last school holidays, I've not managed to visit for a long while, so needed to go, so I was very grateful for this offer.
DF then announces that for the sake of fairness - he gives DB the same amount he gives me to treat himself, followed up by how pleased DB will be, not that he needs it as he's had a big work bonus this week etc etc. this happened once before & DF pretty much forced the money in me towards my train fare - then told me afterwards about treating DB with the same amount to spend on himself.
DB hasn't changed, he's a nasty manipulative piece of work, with a superiority complex & a Walter Mitty persona - boasting to the waitress about his trip to a country she was hoping to go to on holiday, telling her stories about the place - my stories, from my visits - he has never been.
Last couple of times we gave been out for lunch together - a man they know from another town always cones over to say hello - over friendly - DD who sirs next yo DB later asks why the man passed a small plastic pot to DB under the table whilst pretending to rest in the table - this time round, at 11 DD herself tells me the man is giving DB drugs, why else would he do that & yes I agree, it's a drug deal.
It sickens me, it is so unbelievably cocky & disrespectful to DF & to do it in plain view of DD too is just plain nasty.
Lots of sly digs about my weight too, again DD picked up on it - wouldn't mind but I'm an average height size 12 FFS - this culminated in DF buying me weightloss pills 
DDs not I significant allergies - which put her in hospital a few months back - is my being a fussy faddy eater & trying to force it on DD - etc etc
I get fed up of my visits up there, 8 hour journey which wrecks me for days on end - are not seen as my making a huge effort to visit DF, but as us going for a free holiday as it's a holiday town - not one that we like much & we live in a far better one
Anyway - I left the money behind - I thought I had hidden it, with the intention of emailing a well worded explanation to DF on getting home
DF found it just after we left - rang me on the train & I tried to explain that I couldn't really talk then, but would later, but that I didn't feel I could take it as I don't want DB being given money on the back of DF helping me out with train fare, but would explain better later - DF slammed the phone down & followed up with a couple of texts basically cutting me off again, telling me that he gives to us both equally & that I have spoilt it again & BYE!
We don't get given equally at all, DF still dies a lot fir DB, taxis to do his shopping twice a week & meals out twice a week, plus cat good etc - that's just what I noticed when there - which is fine by me, DB is there & TBH I realise that if DB wasn't getting something out if it, DF would never see him
DH thinks I was stupid to give the money back, we need it & it's my fault it's kicked off again
Am I, how do I now handle this - I don't want to cut DF off, but it cannot take money from DF towards the cost of visiting, knowing it means my very toxic, money grabbing, eye on his inheritance, hated DF before losing DM, DB gets a money gift, that no doubt goes in yet more drugs - but how the hell do I say that without telling the whole story & DF does need DB as he us there & I'm not
Sorry, novel - really upst by thus, normally have a tougher hide after years if it, but feeling weak I think as I'm ill & also have been lulled into a false sense of happy families I suppose :-/