Helped my boyfriend of 6 months move flat today. He's lived there for the past 4 years and he mentioned afterwards he felt quite sad about leaving and then said he was thinking of creating a Facebook post thanking his current and past flatmates for the great times he's had there and then proceeds to list them....and within the names he mentions a girl who he slept with on and off for 3 years. They were never in a relationship but enjoyed great sex. When i said 'oh but she was never your flatmate' he said yeh but we spent a lot of time in my room. I said that I thought that was a bit weird to thank her amongst them and he said yeh you're right.
AIBU to feel quite wtf about this or should I just get over it?