Becoming joint owner of a property

[kibbles]

I live in tied accomadation, meaning that should my job finish, then I will be homeless too. My partner/boyfriend owns his own property, albeit with a mortgage. We dont live together. We have talked about the possibilty of my job ending in the next couple of years (a likelyhood) and he has suggested that I might be named as joint owner on his property if anything happens to the job, or even to him. Can I do this without becoming jointly liable for the mortgage?