I am 35 yrs old. I have the same problem. Just like Pepsi143 explained above, I realized the jelly-like substance was very much like what I have been coughing with the phlegm when I had severe allergic asthma. I have never tried recreational drugs. I have sugar & and occasional alcohol cravings.I also have out-of-control allergies.
For the last four months I have been dealing with a more serious problem, which manifested itself as blurry vision, depression, slurry speech, and maddening itches with really bad rashes started around the tip of the penis, moved to scrotum, and finally to rectum... and more sugar cravings. The thread here seems to be carried away from the subject but please continue to read; hopefully this may help a few of you as well. My condition was diagnosed as Candidiasis; a serious fungal infection caused by Candida Albicans which is capable of invading human body according to sources internet sourcces and now to my experience. If your immune system is weak it starts to invade human body, it populates itself in gastrointestinal tract, lungs, upper respiratory system, etc, and poison you with toxins that gives the infected a large variety of diseases.
Especially if you have carb & alcohol cravings, depressive mood(and drug use because of that), history of prolonged antibiotic or cortisone treatment � even one or two amalgam fillings, constipated or having frequent diarrhea - Please Google "candida questionaire" and score your results. It is a collection of questions that measure the likelihood that you may be infected or not.
By the way - that jelly substance appear on stools too, if you are infected. Or a little thread of it wonders in front of one of your eyes and give you an annoying blurriness feels hard to clear and makes you wonder if you drink enough water. It would not help even if you do.
My personal opinion is jelly-like substance of some may be a milder symptom of a Candida infection in addition all other possibilities discussed here.
I have been on Candida diet (life altering event � lost 26 pounds in 2 months), anti-fungal natural remedies for 2 months and Diflucan treatment for 2 weeks now, and jelly like stuff on ejaculation and lungs seem to disappear along with all other problems that I used to live with such a long time.