Parking in the garage? Big deal. If I stayed somewhere and they had a garage where I could park my car, I would do it too. That doesn't mean I'm having an affair.
Staying over night at a customer's house? That would be purely bizarre if in fact there was nothing going on.
Bringing the kids over to stay the night at his house this early in the game? Friends - fine. Lovers - wrong on sooo many levels.
Did she admit to an affair when you went to counseling? You said you went, you didn't say if she confirmed it. If she did admit it previously, and she's telling you upfront that she is staying there again and even bringing the kids, then telling her that "you would have to quit your job, cut all contact with OM, and become transparent. We would both have to start IC and MC and commit 100% to each other. I will not settle for anything less" would push her towards D. She's not in the mindset of reconciliation. DB would say, I believe, to let it run it's course, and protect yourself in the meantime.
