DH was on a work night out last night. He got in at two, which was odd. He was very apologetic about waking me. I knew something was up: I don't know how but I did. At five I checked his phone. There were two texts from a girl I hadn't heard of saying " that must not happen again, just back to normal nothing else I'm sorry" then another message saying " reply to this I need closure". I woke him and asked who she was. He looked sick and couldn't speak... He then said she's a girl at work, they'd been flirting for a few weeks. Last night they went off on their own and 'almost' kissed but didn't. At that point our children woke and we had to stop talking.
I feel sick and I can't stop shaking. We have been together for twelve years, married for seven. Our kids are four and six.
Should I believe him? He keeps saying ' I haven't done anything' but what he's admitted to makes me feel sick. Am I overreacting?