Five years ago, Bob (Alexis Arquette) and Brendan (Christian Maelen) were college roommates and best friends, but their friendship ended when Bob made a pass at Brendan. Now their old friends Matt (Jamie Harrold) and Carol (Lauren Velez) are getting married, and they've both been invited to the wedding in Washington, D.C. Bob is in a monogamous relationship with soap opera star Sterling Scott (Tuc Watkins), while Brendan is questioning his own sexuality.
I Think I Do contains examples of:
- Clothing-Concealed Injury: Bob spends a few scenes wearing a neck brace to hide the hickey Brendan gave him.
- Creator Cameo: Producer Lane Janger plays a bartender at a gay club.
- The End: The words "The End" appear and are then knocked off the screen by "The Beginning."
- Fainting: Bob faints when the fact that he slept with Brendan is about to be exposed. A few seconds later, Sterling and Sarah (Marianne Hagan) both faint from the revelation.
- Flowers of Romance: Sterling brings a bouquet of flowers to apologize for locking Bob out of their room, which only makes Bob feel guiltier about cheating on him.
- Lohengrin and Mendelssohn: Both are played at Matt and Carol's wedding.
- Shaped Like Itself: Bob asks Sterling how his tour of the monuments was. Sterling answers, "Monumental."
- Soap Within a Show: Sterling's character is constantly ending up in the hospital thanks to Bob's writing, for reasons that include his sister's fiancé sabotaging his car and causing it to go off a cliff. At first Sterling thought it was sweet that Bob was trying to strengthen his character - in fact, they started going out after the first hospitalization - but now he's starting to get sick of it.
- Special Thanks: Two screens full of names are listed under "Very special thanks" in the credits.
- Stag Party: Bob and some of the women join Carol at a hen party, where Carol and Bob pay male strippers for a lap dance.
- Tears of Joy: Carol starts crying so hard during her vows that she can't even finish them, saying "Till death do us... whatever," and lunging to kiss Matt.
- There Is Only One Bed: When Sterling passes out in their room, locking Bob out, he is forced to spend the night in the bridal suite with the others, which means sharing the sofa bed with Brendan. They have sex.
- Time Skip: The movie opens with the characters in college, then jumps ahead to the wedding.
