most likely this is irritation or even a fungal infection going on. clean properly daily under your foreskin with a gentle soap and water and if the rash lasts longer than a few days, be seen for proper follow up.
grace
I suffer from health anxiety and think of all possibilities. even if they are not possible, also i did not know if a sti could be created even if we are both clean sorry if that sounds dumb
What would make you think you have a STD from your wife?