Can I ask my friend for her flatmate’s number?

[Anonymous]

I gave her my number, but I think I made a mistake.

Do you think it’s ok if I ask my friend for it?

[SnakeBoop]

You can ask, sure. Doesn't mean you'd get it.
Probs better to ask if she can give the flatmate YOUR number. Less creepy to offer yours

[Asker]

Well my friend gave me her number…

Me: "What's your schedule looking like next week?"
Her: "I'm pretty much free all next week but Tuesday and Thursday are best for me. Do you want to come with (our two friends) to Samba tomorrow night?"
Me: "Sorry I can't make it for tomorrow night. Let's meet at X and have some fun on Thursday at 8pm?"
Her: "You'll have plenty of opportunities to for samba haha... it's a date"

She even replied this to when I said I need to keep practicing my Portuguese "You'll have a pretty good teacher my dear hahahaha"