Thank you @GingerbreadHelen. The link is very helpful.
I should be ok from what that says. The only concerning part is:
Benefit decision makers will consider whether your relative would enforce the agreement. For example, by serving notice to end the tenancy if you don’t pay rent
Because my parents wouldn’t kick me and my son out, but i have paid rent for 10 years and i have a tenancy agreement etc so that should hopefully go In my favour?