cannot find any discussion on this specific question(s)

I realize that each individual is different and reacts different to V and the other ED meds.
 

Does Viagra decrease the sensation of your orgasm?  
And how about round two does it decrease the possibility of that?

I’ve also heard that some guys take longer to cum when using V  

Comments suggestions from guys who have used V and your experience with regard to the above and anything else about V is appreciated

 
I used Viagra with good success for five years.  Then slowly my climax's decreased to almost never. Went to the UR an he says those meds can do that so he put me on Tr-Mix for awhile then to Bi-mix and now they have returned to the way they used to be maybe even a little more intense.  Works great if placed properly. The hard on lasts for me 2 to 4 hours. If I was only younger so I would have the stamina to go that long.   About an hour and I'm done.

I've been using generic Viagra for about ten years (I'm 62).  I get it from a source in Europe when I'm traveling there on business.  In addition to using it for 1-1 sessions here in the U.S., I have also had occasion to go to sex clubs in Europe where there are opportunities for as many sexual encounters you can physically muster.  In that regard, I have had the opportunity to use Viagra knowing that I would have (or try to have) multiple pops during the course of an evening.

In answer to your questions:

1. Sensitivity:  In 1-1 encounters, I generally don't have a loss of sensation, even when wearing a condom.  If I can't cum during covered sex, it's usually because of the same reasons that would happen before Viagra:  fatigue, jet lag, not really into it with the provider, etc.  The intensity of the orgasm is usually dependent upon the same factors as before Viagra as well, including the length of time between sexual activity.  In cases where I can't cum inside her, she can usually finish me off manually within a couple of minutes.

2. Round two:  Here's where my sex club experience comes into play, with probably my age as a contributing factor.  I can usually perform adequately during the second session if I'm not tired or jetlagged.  But, the sensation decreases significantly while the erection pretty much stays.  At an Amsterdam sex club (basically an orgy) a few years ago, by the time of the third attempt, I was still hard as a rock but had no sensation at all.  It wasn't numb, but my penis felt like it was filled with concrete.

3. Length of time:  For me, it varies and is a function of my head and her skills.  I've cum after a minute inside her and I couldn't cum at all.  Ultimately, for me, the Viagra has only a secondary effect.

I've learned to only take what I really need.  I've started out taking 100mg pills only because that's what I could buy.  After reading a bunch of blogs including TER, I started cutting them in half with no loss of performance and a significant reduction in side effects.  For my last session last week, I cut half a pill in half again.  The quarter pill worked great and the side effects were negligible.  I'll get a chance to go back to sex clubs early in 2017 and will try out the cut pills and see what happens.

I believe the best way to lessen the effect of V diminishing sensitivity is to cut the dosage to just enough to achieve erection. I actually consider the reduced sensitivity a benefit if it can help extend the action for the whole hour.   For play time I would rather have the erection than the orgasm.  You can have a lot of fun with an erection.

Guys, do you tell the lady you are using V?

Ladies do you want or prefer the guy tells you he is using V? ......If so why?

Nope.  None of their business.

For one, they probably already know.  After actual penetration, most sex before orgasm are 3-5 minutes long.  If you're fucking her for 15-20 minutes, she'll know something is up.  She'll never say anything, but she'll know.  

Providers don't like it because its harder on their bodies.  So, thats why I wouldn't say anything because she may cut your session short and finish you with a hand job.

I have had a couple of ladies tell me they can tell the difference while giving a blow job.  In my case, I have Peyronies so the 45-degree upward curve is more often the subject of conversation.

If you book through P411, the client's profile page asks if you use performance enhancers. You can say Yes, No or No Answer. The ladies can also see your age so No Answer will be the same as saying Yes if you are 60+

I am older- 60s and found I wasn't getting it up or 3/4 hards and losing them easily.  I read this and other boards and decided to to tryMaster Zone since I could get it online w/o perscription.  Easy and solid erections that stayed up unless there was NO stimulus.  For me they enhance performance for 7-10 days per pill with the only discernable side effect being possible light indigestion on the first day.  I don't have stock in this stuff, but it was a game changer for me.  I have only used for less than a month so if anything changes I will inform the board, but I'm sold.

Just an FYI: FDA as confirmed this product contains active ingredient of Viagra and Cialis

I can go a long time and it can be hard to cum if have not had a reasonable period between dates.
I also use Indian generic I buy through Canada.   cheap.

I've used it for years.  Sensation awesome, but longer to orgasm.  That's fine for me!

I just got 20mg at Costco.  I tried just using one pill with success!😜