Can I Attend a Gay Wedding Without Violating my Catholic Faith?

I recently learned of this Catholic Q&A, which asked Can I Attend a Gay Wedding?:

Question: I understand and agree with the Church’s stance on same-sex marriage. However, is it wrong to congratulate people or attend the wedding of a same-sex couple? Wouldn’t it be similar to going to a wedding of a different religion?

I was actually surprised by the answer. Essentially, his Catholic lay minister responded: Yes!:

While the Catholic Church teaches that marriage is reserved to one man and one woman, this doesn’t preclude Catholics from attending celebrations that aren’t Catholic sacramental weddings. Civil weddings don’t pass muster in the Catholic Church, nor do some unions celebrated in other religious communities. That’s not the point here. Mere presence at an event does not mean approval of everything that is taking place... 

If someone invites you to a gay wedding or to a wedding of a different religion — especially if that someone is a friend or relative of yours — don’t hesitate to go. You are called first and foremost to love that person and to honor the relationship you have with him or her. There is another time and place to discuss the teaching of the Church with respect to marriage. And if you are concerned about scandal, remember this: There’s a difference between a Catholic priest presiding at a gay wedding and you attending one.

I thought that this was a well-balance response. It acknowledged that a lot of folks really feel torn by this question (in fact, it's one of the more commonly searched for questions that I receive these days). Do I violate my faith by celebrating with my gay friend or family member?

If you read her full answer in the linked Q&A, she states the Catholic Church's opinion on same-sex marriage, but then points out something that most Catholic leaders frequently fail to note: same-sex weddings aren't Catholic sacramental weddings. In other words, the Catholic Church might not recognize my own gay wedding. But that same church also doesn't recognize my own parents' wedding because it wasn't performed within the Catholic Church. The same could be said for almost every wedding performed within my immediate and extended family.

And yet members of the Catholic Church attended most of those weddings because they were friends or family members of those getting married and they wanted to celebrate their unions. And the Catholic leadership doesn't actively fight to legally invalidate all heterosexual non-Catholic weddings.