To you this may be a one-time event of no more consequence than the few bucks you contribute, but that's actully callous and unfeeling and not at all the generous thing you imagine. Why? Because you aren't looking at it from his point of view. Sex is a big deal; we have have thousands of years of history telling us that with laws, customs, ceremonies, and all the other stuff from love comics to custody battles, to wife batterings and honour killings. And it's highly addictive.
Most of us are fortunate enough to encounter it and stumble through the process of getting sorting it out—if anyone ever does—when we're doing nothing much else but stumbling everywhere. And most of us need no more help with all that than our family and friends. And one way or another we rely on that sorting-out help for the rest of our practising lives, whether from wingmen, the Men's Clinic or divorce lawyers, or our wives, sweethearts and the wonderful women of this hobby.
This guy is different; the only responsible thing is to leave that whole matter to those who are willing and committed to the ongoing involvement and care he needs and which such an event introduces into everyone's life. If ever there was a case to be made for 'saving it for your spouse' it would be a situation like this.
On the other hand, if you're saying you and your well-intentioned buds are always gonna be there for him, like his wife or his support workers … . Or, to raise the horrible image, to get him a lawyer when he proves he misunderstood how sex works.