Hardware can't give you "trust." Movie companies keep spending money finding that out. Chastity belts fell out of favor because they didn't work. (Kink market not withsdanding)
Perhaps you'd better take some responsibility for contraception upon yourself?
Why don't you get a vasectomy?
No, this is not an option.
Unless you have a very specific medical reason I've never heard of it's an option, you are just chosing not to take it.
Sex is the reason why you'd do the vasectomy
Even 1-2% of failure or constant testicular pain is too much
For her sake I hope your partner finds someone else.