After the incident in September, she told me that she hadn’t been with anyone else during the period we’d been seeing each other. We agreed (at least I THOUGHT we agreed) not to see other people after that.
Call me stupid (you’re stupid!), but I didn’t confront her sooner because I thought there wasn’t any sex going on. I hadn’t heard any sounds of sex coming from her room and, given the lack of information she’d given me, I considered there might be platonic reasons for their sharing a bedroom. It wasn’t until I saw the “penis du jour” remark that I was sure.
Oh, and by the way, it’s OVER.