Should I tell my bf that I masturbate??

Okay so here’s a little background info to this question..

I’ve been with my boyfriend for 9 months. We’ve been intimate and he’s the only one I’ve ever been with, sexually. I’m very self conscious about my body but he loves it. I love it when he makes me orgasm but he’s told me that it hurts his hand (when he uses his fingers to play with me). So I asked him how he would feel if I got a vibrator. & he said “I wouldn’t like it because that means I’m not doing my job to please you.” yet he won’t please me in the way I ask. However, I got a vibrator anyway and did not tell him. I feel guilty for not telling him but he won’t do it sooooo I have to get it somewhere. So should I tell him or no?????