Help my cousin?

Chloe • 17. Christian/Daddy 03/08/16 💕💕
My cousin (16) has been with her BF for 3 1/2 months. Ive met him and he seemed really lovely. However, he gets really jealous and overprotective of her really quickly. Shes having a sleepover at mine (im a girl too, no boys in sight) and we went for a walk and he accused her of not being with me and started yelling. He even saw me on facetime. He got super mad at her for going to see my sick gran in hospital too. Im worried about her as her last BF hurt her loads. 
She said she would feel bad for dumping him because it would look like she was with him for money (he bought her an iphone 6 and a pandora ring) but i really think hes trying to control her. 
Opinions?