he can't cum without a vibrator

So my boyfriend of about 6 months still hasn't ever cum while we are having sex. He was basically a virgin before me so he has been using a vibrator for years to jerk off. Now he is desensitized. He says he has stopped using it and that he is getting feeling back. Does anyone know how long it could take for him to be fully sensitive? Is there a mini vibrator out there we could use during sex that won't continue his loss of stimulation? I just want him to be happy and orgasm with me 😔