(NSFW) How do I get over my phobia of talking dirty in the bedroom?

(NSFW) Oh geez. My boyfriend wants me to talk dirty to him all the time and it’s so hard for me. I get the giggles and it takes me out of the moment. I’m not a prude by all means. It’s just dirty talk sounds so silly. I also feel silly trying. It almost seems juvenile to me to decribe what we’re doing on a base level. He told me it’s like forplay for him. So, I have to try. Especially without laughing. I can dirty text and talk dirty on the phone, but when were together I freeze. I never had to do this with other relationships. I do want to try if he enjoys it. HELP