I received an invitation to my college roommate's wedding, which is happening in three months in a different state. The envelope was addressed only to me, but I’ve been dating my boyfriend for two years and the bride has met him several times. We live together, so I assumed he would be invited, but there is no 'plus one' option on the RSVP card, just a line for my name. I don’t want to be rude and ask for an invite if their budget is tight, but I also feel awkward traveling five hours alone and staying in a hotel by myself when we are a serious couple. Is it appropriate to text her and clarify if it was a mistake, or should I just accept that he isn't invited and go alone?

From The Ladies' Book of Etiquette, and Manual of Politeness: A Complete Hand Book for the Use of the Lady in Polite Society

"True politeness requires clarity—a gentle inquiry honors everyone"

Good manners exist to smooth awkwardness, not create it. A polite text to your friend is entirely appropriate: "I wanted to confirm—is the invitation for me alone, or may I bring David?" This is not demanding; it is clarifying. She may have simply forgotten, or budget constraints may apply. Either way, you will know.

From Pride and Prejudice

"Do not tie yourself in knots to avoid a simple question"

You are a serious couple of two years. If your friend does not know this, that itself is information. Ask directly and graciously. If the answer is "no plus-one due to budget," attend alone and enjoy the day. If she simply forgot, she will be grateful for the chance to correct it. Silence helps no one.