"I wondered if this was cheating"
Wellllllllll ...... not if the recipient(s) are aware of what they're reading*. In the event they're not, maybe they won't notice any difference - maybe there isn't any - when "real" Philip appears, in-the-flesh. As PozBearWI points out above, what's important is that every participant (2, 10, whatever) gets the genuine guy**. As long as that happens, real, fantastic "connection" is available to any/every guy in the writhing clot of bodies.
*AI is a fascinating - well, "thing" - and it can improve all kinds of interactions immensely. But it's inanimate, and people aren't. It may seem/appear to be "animate", particularly when the actual people haven't met (in-the-flesh) yet. I very much hope you give us a description of how the day unfolded - not necessarily the sex part - but more if/how the actual, in-the-flesh meeting was, your impressions of any match/mismatch of the AI persona with reality.
**What I'm unclear about is, how much (in the recipient's mind) is AI and how much is the actual person. I realize that AI can help us understand ourselves, improve ourselves, all of that, but it that result permanent? Do we revert to what we were before we used AI, if we stopped using it? Or can the subtle alterations become permanent in our minds? Or even should they ....