Now that I know he enjoys it yes I’m sure I’ll give him a cheeky surprise finger at some point when the time feels right 
I’m at a point where I want to try anal myself again after a failed attempt a few years ago (here’s my post about that - How to bring up anal after previous bad experience) So I’m very open to anything anal atm and I hope it becomes a part of our sex lives in the future. Starting slow with anal toys for me but him asking me to finger his ass was unexpected and exciting for me as he’s clearly somewhat open to the anal idea again too and who knows where it will lead! We’re in no rush though as we’ve made that mistake before, we’re enjoying the journey 