My girlfriend and father are signing a mortgage and want me to sign a 2 year lease?

Well if she wants to buy a house and it is sounding like a family affair already#### . Then she needs to be sure that she truly wants the responsibility of it no matter what ever happens to her in her life with her home. If she is trying to coach daddy into helping her to impress; that is the totally wrong thing to do! Plus she shouldn't be trying to writ a policy on anyone unless it was understood that that's all your going to be doing is renting a room anything else would like be entrapment to produce funds. If you live with her obviously you know you have to pay where ever you live so why have a lease. It sound to me your not trusted so you might want to think about it hard before you move in ! You might get blamed for everything that busts or happens are you liable to pay for repairs also on a home that is not yours? i would just work out a verbal agreement and sign a paper stating you agree to pay so much as long as you are there and if for any reason you don't make your payment it be at her discretion in writing for you to leave, and you have 10 days to remove yourself from the property.