I need a little bit of advice.

I have a crush on these two girls. I’ve told one of them, but I just can’t seem to tell the other one. Now here’s something you should know about me. I’m a VERY open person and I’ll tell people if I have a crush on them, I also tell my other friends if I have a crush on someone because I love and trust my friends with everything. I really want to tell this girl that I like her but I just can’t seem to SAY SOMETHING. I really don’t know why this is happening. Help a sister out would ya. Please keep it positive.