What’s your relationship advice for this situation?

UPDATE: Thank you. This post has been answered. No need to comment. Thank you

EDIT: thank you to those that replied. I have my answer. I’m being too sensitive and this really doesn’t matter in the grand scheme of things. Thank you!

My (36F) bf (44) and I have been dating 18 months and he booked a flight to see his friends on my birthday.

I’m guessing this was the only date that worked and they’ve been trying to get together for months.

He did tell me before booking asking if this was ok and I said yes (genuinely thought I’d be ok with it), but later felt hurt. He’s promised to make it up another day. I guess it’s the fact that he even considered it and then has treated it so cavalier (“oh haha sorry I’ll make it up!”)