Vibrator

My s.o asked me if I wanted to go shopping this weekend and I jokingly said “okay but only if you buy me a vibrator” and he actually did buy it. Now im just wondering how the heck do you use a vibrator while having sex? Do you use it at the beginning or wait for the “finale” 😂 i never used a vibrator before and now im kind of nervous idk he says he’s excited to use it because he wants me see me “cum” lmao do you and your s.o use a vibrator?