If that is your boundary, it doesn't matter whether he cares. Boundaries are about YOU, not about controlling him. If he does not stop the affair (by whatever date you say, which could be NOW), then stop living in an open M.
-- separate your finances, legally if possible. if he is in an A, he will almost surely spend excessively.
-- make arrangements for one of you to move
-- stop any non-business or non-co-parent contact. A husband having an affair is not your friend, not your lover, not your parnter.
-- get the support you need without relying on him. Protect your interests
-- set up a childcare schedule
-- etc...
If it is an in-house separation, then drop only the moving plans, everything else stays.
RTGU: I will not live in an open marriage H: Too bad, don't care RTGU: Let me be clearer, I will not continue to share a home, share finances, share time with you while you continue to have an A. H: Too bad, don't care, I'm sticking with my nookie-on-the-side RTGU: I see, that doesn't work for me in the context of our M, but it isn't certainly your choice. So, let us first work out a childcare schedule. We can look at finances and housing options later.
