Let's face it. You don't have a costume. Your significant other doesn't have a costume. Unless you intervene, that significant other will likely go as either a creepy clown or Ken Bone, and your sex life can't take a hit like that.
I hope Jezebel can forgive me (luv yaz, 4 realz), but it's about to get real heteronormative up in here.
Let Shinesty usher you to the sweet spot of Halloween coupledom: suits and dresses. You'll look hot, but not too hot. He'll look dapper in a way that only occurs when a man is wearing a European-cut suit. You'll be 0.06% more likely to fellate him because of this, so it's a win-win for everyone.
COSTUME IDEA #1
For her: Bloody Sunday Dress. Add some heels, a red lip, and a fake knife. Bonus: No one will see the red wine spills.
For him: Shower. Put on this suit.
COSTUME IDEA #2
Walking Into Spiderwebs
For her: The Spiderwebs Dress. See our previous advice on what to do to complete the look, like drawing a spiderweb on your face, wearing a witch hat, or using fake blood/lipstick to get that vampy look.
For him: Consider shaving. Eat a hearty meal so you can drink with the reckless abandon of a freshman pledge who just convinced his parents that fraternities are all about networking opportunities. Put on the My Spidey Sense Is Tingling Suit. Let her apply costume makeup to your face if she desires. Please. Just this once.
COSTUME IDEA #3
For her: The Gunshot Dress. Add some dead-looking makeup. Maybe get some fake blood on your face.
For him: The Band-Aids Don't Fix Bulletholes Suit. Add deodorant. Consider the relative pros and cons of hair product.
COSTUME IDEA #4
Money Can Buy Me Love
For her: The Bish Better Have My Money Dress. Look expensive. Oh wait, you already do. *Hair flip*
For him: The C.R.E.A.M. Suit. Try to look expensive without looking like her pimp.
There are some problems only relationship counseling can solve. For everything else, there's Shinesty.