If I might make an additional suggestion, it would be best to veil all of your bridesmaids. The bride and a single bridesmaid hiding their faces looks suspect. However, if all of them are veiled, it will look intentional if a bit eccentric.

[Alastor knows a thing or two about misdirection.]

And if your groom suspects a trick and thinks to unveil a bridesmaid to expose you, better to hide amongst many so he's more likely to pick the wrong one. Speaking as a member of that wretched half of humanity, being publicly incorrect will sting his pride so much that he won't think to unveil more.