Apologies I just saw this post, and I'm going to speak this on general term, and not individuals. Some men and 99.9999% of female will not agree on what i have to said.
Now with that said, I believe we men are wired (by genetics) to want varieties. There are men on here that have SO (wife, gf, sb etc) but your SO no matter what she will do for you, you always want something different, that doesn't mean you don't love your SO, but we just want varieties.
Now to answer the OP question, in my opinion i don't believe participating in this hobby is consider stray. Because the provider here knows that we paid them to leave, after they gave us "post-nut clarity".
This hobby is best because of this, no string attach, i don't have to wind/dine some (so call modern) women in their 20s just to get regular variety sex from them because like other said, most of us doesn't have games.
So at the end of the days, you still will go home to your SO, you will still provide resources and securities to your SO. By that logic, you're not straying.