I have found that (on occassion, not every time) that there are times I can just go and go and go, to the point of exhaustion (I am NOT a fit individual), yet not cum.  It can be quite frustrating though I enjoy the sensations immensely.  I never blame the provider, its me.  Other times I can "pop" twice in an hour.  It seems to have no ryhmn or reason.

Two things seem to cause it for me. One (surprise surprise) is having a bit too much to drink before having sex. If I have half a buzz on, or especially if I have a full buzz on, It takes me literally forever to finish and coming inside a condom is almost impossible. The good thing is that when I am half in the bag I really don't care if I finish, getting drunk and fucking is plenty of fun for me even if I don't finish. It also helps that most of the time when I am having "drunk sex" we are both drunk and neither of us are going anywhere so we can always finish what we started in the morning.

 
The other thing that makes it hard for me to cum is having a lot of sex, it used to be about four times in a day for me to have too much difficulty cumming, but oftentimes at my current "advanced age" even going twice in the same day can make it difficult for me to finish.

 
That said, there really isn't any rhyme or reason to it sometimes, every once in a while I too can "pop" twice in an hour, while other times twice in a day is an effort. I don't "blame" the woman if I can't cum, but I do "credit" the women who can get multiple pops out of me without having to wait hours for me to recharge sufficiently enough to cum again. It doesn't take too long for me to get hard again, but like you cumming again can be an issue. I just chalk it up to getting older.

..... stimulated at the start of the session. I don't let it go because I'm a one and done guy and I am having too much fun, hence the stimulated. So by the end of the session I sometimes can't cum.  

Also, after a BDSM session, my whole body gets so stimulated that sometimes getting my cock over the edge  is difficult.

Then there are times that I shoot like crazy.

Damn, it is definitely time for a BDSM session. It's been way too long.

Have fun.

Age is a factor given

Drinking is a factor given

Ed meds are a factor given

Physical illness is a factor given

Psychology is a factor given.

In the end, it only gets worse when you try to factor in all these things.  

As long as you can over come those givens and say, damn that was an awesome fuck, don’t over think it, it’s likely to happen again.

Drinking can either help or hurt me. There have been times I was wasted and finished fast, most of the times I don’t finish at all.

ED meds like viagra are the worst. 25mg is sufficient to build my esteem and be able to go long or short, but actually be able to finish. More than that, might as well do a porn video of me fucking forever and get a stand in to finish.

Physical health feeling my best plays a big part.

Psychologically I cannot overcome thinking she’s not my type or we don’t click and I am lucky to get 50% strong enough to start let alone finish. The only times I can is usually when I close my mind and imagine someone else I want to fuck.

But ok, move on, write it off to being too old, or watching too much porn LoL

...there have been a few occassions now that I'm in my seventh decade. It hasn't slowed me down and I don't worry about it since there are other things to enjoy. 😎

Too fat, too thin, too bad......

It's the providers fault. If she was doing her job she would have pleasured you in a timely matter.

I have to fight not to come in the first few minutes when the chick starts sucking my cock. But after the first 30 minutes it gets increasing unlikely that I will come ... though I stay hard throughout. It's all fun though. I'd rather not come at all than to come early and lose my erection.

For me, its a combination of the condom and psychological factors.  Before starting in the hobby, I had only had sex with two different women--a college girlfriend I was with for about 3 years, and my wife of 15 years.  Both had hysterectomies so I never once used a condom.   So my introduction to condoms was in the hobby.  I soon found that once the condom goes on, it's like I lose sensation.  I rarely have any issue with maintaining wood, so I go and go and don't come.  Then I worry about it and get somewhat anxious (esp. that the girl will feel like she "failed," and I really don't want her to feel that way)**, and even trying to finish at the end with a HJ or BJ has mixed results.

So I've just decided to not worry about it too much.  I'll use the first half of the date to enjoy the kissing, the necking, the DATY and BBBJ and other GFE fun, and when that feeling comes over me, I don't try to hold off for a "FS pop" (which may or may not happen).  I'll just go with CIM, enjoy it immensely, and then either use the rest of the time for cuddling or massage or chit-chat; or, if I'm feeling rather strong, just enjoying the mutual pleasure of intercourse in various positions without expectation of a second pop.  

**Nothing kills the mood of a date for me more than having an "it's not you; it's me" conversation.  Especially with a K-girl.

A few years ago I was injured in a car accident. My doc prescribed hydrocodone for pain relief to my neck and back muscles. I went to see my 'regular' provider, a 25yo GND type, while I was 'under-the-influence'. In the past I'd usually cum after 5-10 mins of fucking this fit cutie. But this time we reached the 25 minute mark and I was hard & pounding her like never before. She even complimented me for my staying power. After I came, we laid together and she told me how much fun she'd had. She said even her BF didn't fuck her that long without coming, and she'd enjoyed being "pounded" like that. I saw her twice more that month, each time with the same results. By the third time tho, she was becoming a little annoyed at me. While we were fucking she looked me right in the eye and said "god, wouldja cum already?"  Well, my pills ran out soon after this and so did my marathon sessions with the 25yo.  It was FUN while it lasted.

There's a couple of other threads going on about the same thing. The medical term is delayed ejaculation (DE) OR my favorite, retarded ejaculation (RE). Google the terms. It is different than erectile dysfunction (ed).  

I suffer from the same problem. The first thing to do is see a urologist who specializes in sexual dysfunction to rule out a medical condition, ie, low testosterone. He / she should be able to provide advice geared to your situation.  Do some research on urologists or ask your primary for a recommendation.  I've seen a few dummies.  

Good luck. No one should have to live with this problem.

Its getting her into the mood that is usually the problem.  Not this week though.  Happy camper this week.

I just started having this problem a month ago and it is a direct result of too much activity.  Went from about 3 ejaculations per week to 3 per day, I've just been horny as hell and the wife has stepped up her game in the bj department.  I actually went about 45 minutes without cumming during an excrutiating bj session where multiple re-marriage proposals were offered.  Additionally, once the load is delivered after a long delayed ejaculation, the penis softens like almost instantly.  I expect to get back to normal once I slow down, if that ever happens.

Just kidding, I like All Sizes..and harder  longer..Then  The Big O

Providers often seem disappointed when they can't make me cum because they think I didn't enjoy it enough. I honestly don't care very much though. I don't know why it happens, but often times I just can't cum. I still enjoy sex tremendously though, I don't need to cum to enjoy it a lot.

I have been this way since the time I lost my virginity at 20, even if bare. Enjoy the longer time, don't worry if you don't ejaculate (she isn't trying to get pregnant with you anyway), and be sensitive to not making her sore. Some women really enjoy it if it is gentle enough.

I'm in my mid-40s and decided to take the Blue Pill ( from time to time ) to stay "at attention".    I found that it does help with keeping me up. But one of the first times that I had a session with a provider, I ran into the same problem that you had mentioned.    Given that I only had an hour, it was a little bit of a concern for me as I found it hard to cum.    There maybe some variables that may have contributed to this ( use of a condom that likely reduced senstivity since I am used to going BB with my SO, was nervous at first but it definitely wasn't for lack of trying from the provider ).   I eventually  was able to finish the deed after having some additional stimulation.  

I'm not entirely sure what was the cause was,  but I likened it to the Blue Pill ( afterwards ).  So I take it sparingly ( depending on how long I'm going to spend time with the provider ).

It seems to be that way with me, even though I am slow anyway.

Reassure her in advance that if you don't come with her it isn't about her.