A 22 year old, and obviously not a virgin. He's inexperienced with having any sorts of relationships because he's never been in any long-term. Sleeping with him was always a disaster because the moment we start (literally the first 30 seconds of having sex), he cums. Why?
Some guys come quickly or prematurely for a number of reasons, I think its more important for you to concentrate on a cure rather then just a reason, this is something that you can do together. john_bees comment is actually a good one, as it will take more time for him to come a second time, but might be a short term release rather then a cure.
There are a number of exercises that will help, most relate to training the reflex to come, or some treatments desensitize the penis. (Maybe free condoms from the clinic. as no man can feel a THING through those puppies)
Here is a website that can help you with PC (Pubococcygeus) muscle training, link
Also its important to talk about it. how and when is a subject for long debate, but if I was your lover I would appreciated it if you could help in anyway. also the treatment ideas are really a two person sport, as they involve you clamping the base of the penis before he comes.
I'd say that means he has some kind of problem that needs to be addressed, maybe medical or maybe emotional or even physically. It's like he can't "handle" being with a girl sexually without blowing his wad prematurely as soon as his thingy touches yours. I'm wondering if it's the same with having sex and getting a hj. I could make some suggestions but I don't want to do that on here.
He has no sexual stamina or staying power. He may not masturbate enough, or it could be a medical problem. That's why guys usually masturbate before a big date. It's been my experience that the more you're with one person the longer end up being able to last. I've been asked to hurry up on more than one ocassion in longer relationships lol. On the guy's end, staying power is a skill that takes some planning, preparation, and practice.
This can be caused by emotional or physical reasons. Stress, Anxiety, Fear for example can play a role in this. What helps is trying to get him to relax as much as possible and also try this...
Premature ejaculation is not caused by over sensitivity in the penis, therefore desensitizing creams/sprays or even circumcision is not the answer. (who would want to have sex and feel nothing anyway :S)
The problem is actually in the brain. The neurotransmitters are firing all wrong because of poisons in the food/water that affect men. They affect women too but in a different way. Ever notice the high percentage of women these days who have breast cancer, cervical cancer or cysts ?
To correct this problem is simple. Firstly, there is a supplement (CHEAP) called Melatonin... buy it, take it at night. It helps with a multitude of problems by helping the body to heal itself at night and also it regulates serotonin which plays a role in ejaculation.
Secondly, there is a herb called Vitex, it decreases prolactin so that increases dopamine (great for eliminating all PMS symptoms in women and also it decreases refractory period in men) so in other words he can go again and again without having to wait very long.
Lastly there is green tea. you can actually drink the tea (I don't recommend this because it's HOT lol I live in the Caribbean so you know I'm not friends with hot drinks) or just take the herbal tablet.
All good advice and all CHEAP supplements available without a prescription.
Also, AVOID artificial ANYTHING (aspartame, etc) they work on a mutated form of amino acids eg. phenylalanine is used to make aspartame and phenylalanine is also a precursor to Dopamine so mess with artificial stuff and your body is gonna take a beating, starting with the smallest appendage :P)
One side note is make sure he doesn't cheat... I had a friend with this problem so I told him what to do. The problem went away, his wife THOROUGHLY thanked me with cookies and baked goods for a month, THEN he started humping up the neighborhood (wife's words)
He literally thought he was God's gift to women and went at it like he could win an award in the Olympics.
Hope this helps... I love herbs and cheap alternatives to solving problems :)