This is the best safe sex you can both have, just keer yourselfs clean and things will be OK.
Good Luck
As long as both your hands were clean, you should be fine.
Other than giving each other orgasms....? I would have to say if your hands weren't washed then the only thing I can think of is bacterial infections.
No risk of any STD's or pregnancy.Maybe bacteria if his hands or your hands weren't clean.