@Barry2021,
It is not clear what your goal is. Are you trying to reduce the risk to yourself? Or, are you trying to force your step-sons to try to do something they don't want to do.
I suspect that the risk to you and your wife is very low, since you are both vaccinated. It depends on the current numbers from where you live, but even in the current worst spot, vaccines are proving to very effective at protecting the person who has been vaccinated.
If you are trying to force your step-sons to do something they don't want to do... you probably won't have much luck. This never works and you run the risk of damaging what I assume is an important family relationship, at least for your wife.
I would let it go.