Heizou, isn't a very.. innocent minded boyfriend, he'd probably say the most inappropriate and jaw dropping thing in public on accident even if he thought about it before speaking

One day he's accompanying you at a party, as one of your friend's suddenly ask you what car you have

"Oh, I like riding any car-" you didn't get to finish your sentence before Heizou interrupts

"Me next." He suddenly blurts out, before your friends jaw drop