<prompt> Human: Thanks in advance for your thoughts rpersonal finance! This situation is a bit complicated so apologies for the wall of text. I am 27, making 70K a year with a 25 EOY bonus I am likely to realize living in NYC. I rent, have no car or other hard assets, and have about 70K in student debt which I am paying down 10-15K per year. I also put 200month into a retirement account. I have an excellent credit score.My dad is nearing 60. He has decent credit but a bankruptcy on his record from my parents divorce about 10 years ago. He also makes 70K or so a year as an accountant. He has some retirement assets but not enough IMO. He was named the executor of a family trust when his parents died 4 years ago, 13 owner of its assets along with his two sisters my aunts. The trust contains a rental property with two units upstairs and downstairs in a very popular beach town. At the time my dad became executor, the propertys downstairs unit was paid off, and the upstairs had a mortgage - it has about 170K left to pay off, and the payments are high 2800 per month. The property brings in about 30k a year in rental income from the summer rental season. At the outset, the trust also had about 50k in cash which was supposed to be used to maintain the property mortgage, property taxes, flood and rental insurance, realtors, and upkeep which can be a lot - we have had to replace a central air conditioner, repaint, clean carpets etc.. However after four years, even with the rental income, all of the trusts money is gone according to my dad. He says we need to remortgage the upstairs to decrease the monthly payments and make the property profitable YOY. Taking the mortgage payments from 2800 to 900 by extending the term from 10 years to 30 years would significantly lower the propertys costs. However we also need to make some substantial improvements - replacing the outer decks which are wooden and falling apart in the salt air and harsh winters, getting a new hot water heater, carpets etc. - about 30K in total according to my dad. About a year ago he asked one of my aunts to cosign the upstairs remortgage with him as she is the only other family member with strong finances and good credit. He cannot get approved on his own. She refused - largely because she thinks my dad is an irresponsible manager of the finances. She accused him of dipping into the trusts funds himself. Its true that my dad is very cagey about sharing details of the finances, and he is the only one with access to the accounts. I know he has spent some of the money himself on family meals and things but he maintains that the amounts were small and that this spending is offset by the personal funds he spent this summer to pay the mortgage and replace an air conditioner when the trust went broke. He told me he dipped into his pension and spent half of it 20k or so to keep the property alive.So here is my dads latest scheme to avoid having to sell one of the units outright which he doesnt want to do as he feels his parents wanted the entire property to stay in the family: he has asked me to cosign a mortgage to buy the downstairs unit with him. The cost for the unit is about 450K, but my dad would contribute his 13 equity to bring that down to 300K. He thinks we could get a 30-year mortgage for that which would lower the monthly payments to 900-1000. The funds from our purchase would go into the trust. Dad would use them to pay off the upstairs mortgage, make the improvements, and then there would be approx. 100K left to replenish the trusts liquid assets...and the propertys expenses would be reduced due to the lower mortgage payment to make us cash flow positive using only the annual rental income to cover expenses and upkeep. Obviously I am very nervous about cosigning with him - I already have a ton of debt, and I love my dad but share my aunts concerns about his financial management of the property. However he says there is no risk or cost to me as 1 the trust will pay us to cover the monthly mortgage we are taking out, and 2 the property will be cash flow positive from our rental income with the lower mortgage. He also says I will get a substantial tax writeoff which I could use...I am in a high tax bracket with my bonus and have no writeoffs other than a small student loan interest one and a hard asset through my co-ownership of the property.This is an emotional decision for us as well as we spent many happy times in this property with my grandparents; none of us want to sell, even partially. There are lots of memories in the house.Is this scheme even legal? Should I even consiser it given my student debt? My dad says my aunts each 13 owners have no control or decisionmaking power legally as he is executor...but I dont know how they will react, particularly my one aunt who accused him of mismanagement and apparently has threatened to sue...Thank you for your advice!!  <response>: Your dad is a shit accountant. This doesnt make any sense. And saying tax writeoff means spending 3 dollars to get one at your income level. Please dont do this. 