I really do think this couple's heart and priorities were in the right places, but I think what the groom actually said...came out wrong, at least. And then there's the fact that the couple pressured the OP into doing a "job" at their wedding, and one she obviously wasn't very comfortable with. See the parts I bolded.
(As an aside, we don't seem to post many Perfect Bride stories as Classics.)My high school friend Jerri announced her engagement in 1981. I was overjoyed for her...until she told me they wanted to sing at their wedding. My voice is, at best, marginal. She pointed out that we sang this particular country-and-western song all the time together. I said that was different - no audience. I'd be glad to play the piano for the singer, and be a bridesmaid, but I couldn't sing. Jerri and her fiancé ganged up on me and I'll never forget what her groom said: "If we wanted a performance, we'd hire Crystal Gayle. It's YOU we want in the wedding, and we don't care if you sound like a bullfrog." I went to the wedding and managed to get off-key only once. They thanked me profusely, and I'll carry the memory the rest of my life. They didn't care about a great performance.... they really wanted ME there. I'm happy to report that they're still together.