I've never dated anyone that was/is deaf either. If its in reference to past relationships, I don't see why a hearing person would leave you for dating a deaf person.
However, if you're dating more than one person, I hope everyone knows and has the mutual agreement, otherwise it'll come back to bite you in the arse.
It really all depends on the type of relationship you have. If its monogomous anyone would be upset your seeing someone, else regardless if their hearing or deaf.