Nc for this as could be outing.
About 4 years ago I started a new job in a large marketing company - lots of offices, departments etc. To cut a long story short after a few years I started a relationship with a manager in one of the other teams. He's a bit older than me and it came as a bolt out of the blue that surprised us both plus our colleagues but we are very happy and been together coming up 3 years now.
The issue is that he has a girl working for him who is around my age who clearly has a crush on him. She has always been giggly, flirty and over friendly with him. Since we got together I thought it would calm down but if anything it's got worse. If ever she texts or emails him about work it's always 'hi hunni xx' and so on. When we first got together she was very cold towards me and gossiped about us at work basically making out the relationship wouldn't last and was a joke. She's a bit friendlier now but still offish at times. The other day I was having a chat with my oh outside the office and she pretty much came over and barged me out the way to interrupt the conversation.
I have asked oh if there is any history between them which he laughed at and said no. He recognises she is over friendly and seems to find it tedious but she is his staff so he needs to be nice. Also spoke to other trusted colleagues who don't think anything has gone on. I've really tried to rise above it - I know how petty and immature it would look to start a row over it especially with it being work colleagues. So I've tried to remain pleasant and professional always. But aibu to think she's a cheeky cow who needs to back off? It's honestly embarrassing to watch her fawning over him at times.