<human>: Could you distill the essence of the text into 1-3 sentences?

As the title says, my boyfriend (M25) of seven months was asked by his female friend (F23) if she could take him out for dinner on his birthday.  Just the two of them.  Does anyone else see this as inappropriate, or am I being possessive?

I'm supposed to work that night but I secretly took it off because I wanted to surprise my boyfriend but now I can't because of this chick.

His birthday is in two weeks so I still have time.  What do I say to him?  I feel like he's going to think I only took the night off because I was jealous of their dinner date.  (Which I am) But I took the day off a long time ago.

How would you feel if you were in my situation and this was your boyfriend?  Any advice?
<bot>: I feel like a female friend is crossing boundaries and doing something inappropriate.  I'm afraid to say anything because I don't want to come across as possessive.