Going Further?? Please help.?

I have been dating my boyfriend for over four months, and I really truly care for him. We kiss and make out alot, but we ALWAYS keep our clothing on. Neither of us want to have , but I do not want to do anything more with him (finger, *******, , etc). It is not because I don't love him, but I want to save everything of that sort for marriage. Making out is my limit. I don't want him to think that I don't love him, but I just don't want to do those things. I wouldn't feel comfortable with it. He wants to do more, and keeps asking me about it. Every time I tell him no, and explain that I want to wait til I am married. He acts like he understands, and says that it doesn't matter to him whether we do those things or not. But then he asks me about it again a couple weeks later. I'm really getting pestered by his nagging about it. I have absolutely no desire to break up with him, but I am not going to give in for him. What do I do if he keeps badgering me about this? It stresses me out and makes me worry that he will not stay with me if I don't do more.