Not so many years ago, child signed a mortgage with parent chikd didn’t have any financial gain when parent sold the house for a profit and brought a bigger house (which they were no longer a signature on.) They just did it to help out when parent needing it. Unknowingly at the time child gave up any future perks of being a first time buyer.
Now the same child needs parent to sign as a home owner guarantor so they can rent a property with their children. They have never had rent arrears, no anti social behaviour etc etc and been renting for 6+ years.
YABU - your parent shouldn’t sign as guarantor just because you helped them
YANBU - parent should sign to return the favour
& yes, I am child 😂