Am I over sensitive?

I went out with a friend last night and as soon as we sit down she gets a call on her mobile and has (what felt like) a lengthy conversation on the phone. Then a text and began texting whilst half heartedly asked me what I've been up to. She then said she'd invited one of her other friends along (who I don't know) along to join us later (she did this last time we met). I left shortly afterwards this other friend turns up and left my share of the tab on the table. I get a text today saying, do i owe you any money 'cos' I didn't pay anything last night, so presumably didn't settle the tab either (rather embarrasing as my local)..... perhaps I'm oversensitve but feeling a little 'used'! Any views??