You’ve both been dating for a while. Xiao is good with words normally, but never when he’s trying to voice feelings of any sort. When it comes to his affections, he’s much more likely to try and physically show you that he loves and appreciates you than say it even if it’s a bit awkward still. So he bites you. He doesn’t always understand jokes, and gets confused with certain things (like intimacy beyond simple kisses, hugs, hand holding).