spidir

In your case, it seems like the awkward part is already behind you. You know he advertises massages, and he knows you've seen those ads.  You really can't put that genie back in the bottle at this point. 
If you are both comfortable with it, I'd say go for it.  Otherwise, you'll probably spend time wondering what it would have been like than regretting giving it at try.
One time I was at the Gay 90's downtown in the Men's Room the men-only bar inside the club, where the strippers came in between sets.  One of them turned out to be a former employee of mine.  He had worked part-time for me while he was in high school.  Now he was in his 20's and honestly couldn't believe it--it was the last place I expected to run into him.
I had always assumed he was straight.  As it turned out, he was.  He was dancing and stripping because the money was good.
I tried to slip away before he noticed me, but it was too late.  He walked right up with a big smile and asked how I'd been.  We chatted for a couple of minutes.  I had always assumed he was straight.  As it turned out, he was.  He was dancing and stripping because the money was good.
I told him I was going to walk around the rest of the bar--really, I was just trying to get out of there because the whole situation felt awkward.
Instead, he smiled and said, "Wouldn't you like to stay and get a lap dance?"
I laughed and told him it would be weird.
He grinned and said, "You know you want to."
He was right.  I caved.
The lap dance itself was fine, but that wasn't really the point.  My heart was pounding the entire time.  It was equal parts exciting and surreal because I had known him years earlier in such a completely different context. I'm so glad I agreed to the lap dance.  I still remember his smile (and his incredible body) to this day. 
So again, go for it if you are both comfortable and it won't be weird when you bump into each other in the future. Enjoy!  

I think it would have to be awkward. Do all your mutual acquaintances know you're both attracted to men? Do they know one of you hires sex workers? Do they know onenof you IS a swx worker? Do you want your provider to know where you live?
Yes, it may be a turn-on to be with someone you didn't know was available to you, but I would find it more stressful than erotic, especially after the fact.
Easy pass. 

I can speak from the other perspective. I’ve been hired by people I know, friends and acquaintances. Given the type of massage I do it can be kind of awkward. There’s an additional dynamic when you know someone but my view is that given they want to hire me, and they understand what I do, I treat them exactly the same way I do ‘normal’ clients, including charging the normal rate (no ‘mates rates’). Actually if they ask for mates rates I find that even more awkward than being nakedly intimate with them!!! 
My advice is think carefully and if you decide to go ahead don’t ask him for ‘mates rates’, tell him you want him to treat you like any client and assure him that if he’s not wanting to accept you as a client he can decline and you won’t seek any reason or let it affect your friendship. If you can’t make that last point genuinely then don’t even try to book him. 
 

I guess it depends on how well your tailor measures your inside leg? 
When I increase my prices I update them on my website and inform regulars when they book. No one has complained. People expect things to go up: prices, cocks and things going up their hole. It’s normal. 
 

I recently experienced a 50% price increase from two of my service providers: a young Russian escort and my tailor. I wasn't happy about it, especially regarding the tailor. 😅

Takes me back to sitting in the audience at the 55th Street Playhouse in NYC. Could get wild and wicked.

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