Would you be mad? Girl asked my bf out!

Heather
There's this girl who is obsessively in love with my boyfriend. She texts him daily and frequently asks him out. She's even had her friends/family try to reach out to him to get him to go to dinner with her. 
Now, I'm not really the jealous type and my boyfriend has been completely transparent about this situation and we even laugh about it. This has been going on since before we even started our relationship and I don't feel threatened at all. He shows me the texts, tells me whenever she asks, etc...
Here's what gets me though...
She KNOWS about me. And continues this behaviour daily. Perhaps even more aggressively now. Is it just me or is it horrendously disrespectful to try and steal the boyfriend of a pregnant woman. Should I be mad? Would you want your boyfriend to finally tell her to give it up? Whenever I start to seem annoyed about it, he's all like "oh she knows nothing will come of it, she's just friendly"
It's just the implication of it though. Like "I know you and him are expecting your first baby together and are deeply in love in your committed relationship but hey let me go for a ride". Like, what is this? Have you ever been in a similar situation? What do I do?!? 🙄