Is OTHER wrong in the post ? POST : So I recently moved out of my rented flat(which I loved, rip) I shared with my friend and moved in with my dad as I have gotten into a bit of debt and my dad said I could live with him rent free in his spare room until I get back on my feet. The only furniture in the room besides my own is my older sister's old bedframe and mattress. My sister has never lived at my dads before but she has moved flats numerous times over the past few years, her last move being to an already furnished flat so she was using my dads spare room as storage for her old bed, it had been sitting there unused for about a year. 
My sister was fine with me using the bed at first but about a week ago she messaged me saying she's moving (again). She's obviously very excited and sends lots of photos of her really nice flat and then she tells me she's gonna need to bed back.
I say that's fine, ask when she's moving in and she tells me she gets the keys in a few days but is still trying to get out the lease on her current flat and will take another 3 weeks. 
My mum(who was on holiday at the time) called sometime later and said she'll go halfers to just get my sister a new bed for her flat so I didn't have to worry about getting a new bed for myself and said that we can sort out costs when she gets back in a few days. 

The next day my sister gets the keys to the flat and won't stop messaging me for the money for the new bed. I told her just to wait a few days so mum could help me out as I was having money problems. She then calls our dad asking him to give her money, so I tell her again that me and mum are going to pay for it in a few days and to stop with the constant messaging. My sister isn't the most patient person. She then messages back about how nice she is being about the whole situation considering I'm sleeping in her bed and she needs to order a bed right now because it takes a while to arrive. We start to argue so eventually I just say 'If you want your bed come and take it, I'll sleep on the floor I don't care, but I'm not giving you any money'....am I the asshole here? 



 
