would you get mad if your man was buying tickets for another girl ? **UPDATE ***

I'm so fukn mad !! Well I have been with my bf for 2 years I'm 19 he's 22. Well 3 days ago he left to Mexico with his dad and cousin to go to the party's that his culture do each year . Well today I went on his fb and I saw he had this conversation with one of the girls over there telling her if she was ganna go to the rodeo and she responded with that she wasn't sure yet and he told her "take your sister so she can be with my cousin I'll buy you girls your tickets" like ok ? I never ask him for shit I never tell him to pay for shit neitheir does he buy me shit cuz he's so stingy but yet he wants to look alll good buying tickets for this other girls . Am I over reacting or do I have the right to be mad ?? 
**UPDATE**
For that one girl that said why I couldn't go is because I'm working and I do have to do a 2 weeks notice that I'm leaving to Mexico so they can give me permission and plus I didn't go cuz I had bills to pay and ALSO he never invented me to go and if he did he would make me pay for my ticket bcuz he would say "he dosnt have that much money and has stuff to pay " I know he's words already . Also I did confronted him about this and he's reaping was " babe there's nothing wrong with hanging out with them I have known them more than you " once he said this I decided to end the relationship I felt like he was chosing them over me  . He chose them over the love I feel for him it does hurt me to leave him but  I can't keep accepting this plus back in New Years he cheated on me with his ex and I think it's time for me to put a stop to it even though it hurts like hell and I'm super sad but it is what it is .