He said he might want to marry her,what should i do?

I was talking to this guy for seven months. he has a different way of dating, he gets to know the person if its good than he offers the "friends with benefits" sex is a big thing for him in a relationship so he thinks thats the best way to date so he already knows if they "tango" or not. After holding the FWB relationship if he feels a strong connection then he will officially make her his Girlfriend. Anyways Him and i stopped talking for 6 months over something someone caused. He said very hurtful things, called me a hoe, bi*$h and everything in the book. It really hurt because i really love him and he didnt listen to anything i had to say.so now 6 months after that he starts talking to me again and we talked things through, we went out for dinner and tried kissing me so i know atleast think he stills feels something since i know him and i really did have a strong connection and would have had something if it wouldnt of gotten messed up, but he talked to me about a girl he met. hes known her for about 6 months now she is apparently everything he wants and she wants to marry him already. He doesnt feel ready to settle down yet so he says thats the only thing that holds him back. Should I tell him I love him? will it maybe change the fact that he might want to marry her? what should I do? or should i leave it alone since i do feel i cannot compete with her shes 28 im only 19 and hes 25.