My daughter is 16 and her boyfriend is 18. I pay for her car and her insurance, she works and pays for gas an

and misc items. They have only been going out for 5 weeks and she now has informed me that they are having . (her first I am hoping, first that I am aware of anyway). Within the past 3 weeks, he has had "car trouble" almost every day and she has allowed him to drive her mustang that I pay for. I was mad when I found out, but yet she still has asked if he can have it while she works if he is off of work, or while she is at school while he is taking cles in college. I always end up saying yes but only after a very mad session.. Now she is going away for the weekend with school and has asked for him to have her car from Thursday until Sunday. I am so mad and yet said yes out of quilt for looking like the bad person. I do not have alot of money and already stretched to pay the payment and insurance. I feel like he is using her, all I ever hear is how he doesnt have rent money, or this or that. Am I being stupid for resenting him using her car. I am normally a giving person.