I take it there are no other procreative options at each time. I.e. at t1 you can either keep John (@10) or switch to no-one. You switch. At t2 you can keep no-one or switch to Alice, etc. Raises interesting issues about diachronic consistency. E.g. if you foresee where you'll end up, then the original choice is wrong (you aren't really switching to "no one", but to John@5, while John@10 is an available alternative). If you can't foresee the future options, it's maybe not so obviously impermissible to get tripped up in this way. I expect there are standard things that defenders of intransitivity / cyclic preferences say about these sorts of situations...?