Have you sneezed when you were turned on?
Have you ever had a nose block when aroused?
How about had sex when you had a cold and immediately noticed a drastic decrease in your nasal congestion?
Research shows that our nose contains the same erectile tissue that is present in a penis or a clitoris.
CASE STUDY (1972)
PATIENT HISTORY: No psychiatric morbidity, 69 year old man
PRESENTING SYMPTOMS: Severe sneezing immediately after orgasm
What is your diagnosis?

When we speak of Erectile tissues, they exist as either as Corpus Cavernosum and/or Corpus Spongiosum. For example, penises have two Cavernosa and one Spongiosum: the former engorges with blood during arousal, the latter, surrounds the urethra, keeping it open for urine and semen to pass through. In our nose however, we just have the cavernosum which is responsible to regulate the nasal congestion.
Now with any cavernosum, if blood flow increases to the tissue, the tissue is said to engorge. In penises, that provides an erection. In the nose however, due to space constraints, it blocks the airflow into the nose. This occurs when certain olfactory stimuli, like chemical signals bind to olfactory receptors, causing a cascade of events that results in the erectile tissue in the nose to be aroused. Sometimes, having sex can cause the same blood flow to be redirected to the genitalia, thus clearing up the airflow in the nose.
While humans don't have any pheromonal system (do refer to my other detailed article on an explanation for this), there does exist a chemo-signaling arousal pathway that functions alongside our olfactory functioning. It was earlier proven that the Vomeronasal (VNO) pathway, which is generally indicative of a pheromonal function is dormant in humans. Thus chemical signals that correlate with arousal, should be utilizing a different pathway to get the job done.
Enter the AND Stimulus - 4, 16-androstadien-3-one - commonly referred to as a man's sexual pheromone. When inhaled by a woman, it increases her Nasal Airway Resistance (Rna). How and why that is important is because, AND inhalation by a woman on the ovulatory cycle of her menstruation, causes nasal tissue swelling, which when one does have sex, that swelling drastically goes down. However, inhaling AND is also associate with hypoxia where limited arterial oxygen, may cause discomfort and pain during penetration, and reduced arousal in the genitalia.
Another condition, hilariously nicknamed as the Honeymoon Rhinitis, is congestion caused during sex that can display a variety of symptoms including sneezing. A study conducted with 23 allergic subjects, honeymoon rhinitis was prevalent in all of them immediately after sex. They say that emotional excitement and anxiety might trigger post-coital rhinitis symptoms.
So how are your Nose Boners treating you so far? What are your symptoms?
Bhutta, M. F., & Maxwell, H. (2008). Sneezing induced by sexual ideation or orgasm: an under-reported phenomenon. Journal of the Royal Society of Medicine, 101(12), 587–591. https://doi.org/10.1258/jrsm.2008.080262
Eccles R. (1983). Sympathetic control of nasal erectile tissue. European journal of respiratory diseases. Supplement, 128 (Pt 1), 150–154.
Kahana-Zweig R, Geva-Sagiv M, Weissbrod A, Secundo L, Soroker N, Sobel N. (2016). Measuring and Characterizing the Human Nasal Cycle. PLoS ONE 11(10): e0162918. doi:10.1371/journal.pone.0162918
Mazzatenta, A., De Luca, C., Di Tano, A., Cacchio, M., Di Giulio, C., & Pokorski, M. (2015). Swelling of Erectile Nasal Tissue Induced by Human Sexual Pheromone. Advances in Experimental Medicine and Biology, 25–30. doi:10.1007/5584_2015_190
Monteseirin, J., Camacho, M. J., Bonilla, I., Sanchez-Hernandez, C., Hernandez, M., & Conde, J. (2001). Honeymoon rhinitis. Allergy, 56(4), 353–354. doi:10.1034/j.1398-9995.2001.00054.x