I don't think that that's annoying him. If you two aren't very close, then you should talk about basic topics such as what you like to do or what did you do that weekend, etc. If you are close to him, then I guarantee that you aren't annoying him because he considers you a close person but don't get too carried away with it and just do whatever with him because you have to remember that if it's a person that you want to have a relationship with, you kind of have to be caution about what you say to him or else he might think that you just want to be friends and nothing more (trust me, did that, done that, don't want to go back). Plus twice a week isn't going to annoy someone, trust me. Everyday on the other hand, might, especially if you aren't close. I hope that helps. Best of luck to you and your crush! :P