I recently did an OH&S seminar on personal care (I work in community care). I avoid anti-bacterial products at home because I believe they are bad for our immune systems and the environment. They gave us anti bacterial hand wash so I raised the issue there. They said that we meet enough germs in every day life to boost our immune systems- and that hand washing with anti bacterial products when required won't be a problem.
I also learned that lack of hand washing is the cause of when we keep coming down with the same virus...we reinfect ourselves.
I guess to sum up what I'm trying to say, soap and water will not harm our immune systems because there are enough bugs around anyway. As for your guy, don't touch his phone or computer. Apparently they can have more germs on them than a toilet seat.
Never regret anything that has happened in your life. It cannot be changed, forgotten or undone. So, take it as a lesson learned and move on.