EASY 10 POINTS...I just need help with being shy!?

I have known this guy for about 5 months, and he lives 45 minutes away, yet we have hung out for like the past 3 weekends straight. We text CONSTANTLY and I am myself we text. But he is a really tall person and his personality is somewhat intimidating..so therefore I am extreamly quite around him. I don't want to be, and each time I have hung out with him I seem to open up just a little bit more. He says he likes me and I like him, but downside to that is that he is a "player" and "heartbreaker". One of the reasons I am really quite around him is because he is also a pervert haha and anything it seems like I say he comes back with a "That's what she said" I just need some major tips on how I can be myself. I have been told plenty of times that I have a great personality but I can't seem to show him in person. If you could PLEASE help me that would be fantastic... :) I will probably be hanging out with him again soon so I WANT to show him my actual self! Please and Thank you!