I don't think the stuff downstairs is going to be the same after the surgery so I'd probably leave. If it's as good as 'the real thing', there's a good chance I'd stay though. I won't lie, sex is important in a romantic relationship and if there's a problem, the whole relationship has a problem. Of course there's other things as well but for a romantic relationship to be worth all it takes, it's got to give enough back.