My partner is much older than me. Is our relationship unsustainable?

We have had a very happy two years together, but have kept our relationship secret due to perceived social stigma

Iam 25 and my partner is 56. We are in a gay relationship and have been for two years. We have kept it secret, however, due to the age difference and the perceived social stigma attached. I am completely solvent – indeed, I pay over my share – so this is definitely not a sugar daddy arrangement. I also had a happy childhood and have no “daddy issues”. I have always been interested in older men, but never thought it could work because of the age gap.

It started casually but we both soon realised that we were very good together and have had a very happy two years. But is a relationship like this unsustainable and am I going to hurt my partner more by continuing it? Or is there a possibility of somehow making it work and everyone around us accepting it?