To me, that seems rather rigid and formal, but more importantly, it’s an agreement between two married adults.
I think it’s kind of sweet. Like something a dating couple would do during the engagement. Every wise couple has their own way to preserve that quality of specialness that attracted them in the first place. It’s their business.
Pence seems to be a serious Christian, and there is something to be said for “avoiding the near occasion of sin”. We don’t just try to avoid sin, but also situations that lead to it.