Original plan changed without telling me

[ThePerkyCoralPoet]

So I agreed to meet up with my friend, I said we could meet up as just the both of us. That was the plan. She helped me with securing a job by sending me interview prep etc and so did her partner. I got
rhe job and that was because of them both partly helping me. I then said we’d get dinner altogether on another night(which I could get). We had agreed that it would be just her and I getting dinner today.

This morning she texted me saying her partner would be joining us. Which is fine I don’t mind but I didn’t account for paying for this meal so now I don’t really know what to do. I know it’s not really socially acceptable to turn around and ask that either. Like are they expecting me to pay?

Tricky seeing as they both helped you with your interview prep.
Can you afford to pay for the pair of them?

Was your friend aware you intended to pay?

It’s just I think it would have been appreciated if I was told maybe last week or something so I knew.

In this situation I'd say something similar to "I had planned this as a treat for you for helping me, I can't stretch to paying for you both, but as long as the cost can be split between us all, I just wanted to clarify so there was no confusion when it came to the bill"

Why have you got two threads about this?