The fate of Ms. Schiavo

one of your main arguments is that because he has another relationship, he cannot still love Terri and therefore is not capable of making a decision in her best interest.
What then do you say to the scores of people who have lost their spouse, and then after a reasonable or even prolonged period of mourning begin once again to date and eventually marry someone they love?
Why does the church even allow widows and widowers to remarry if it violates the sanctity of their first marriage? More likely than not, it is because they agree that you can find love a second time without violating the love you can still hold for those that have passed on.