if you're Miles....
....at what point do you draw the line with Jack's "shenanagins" ?
Even if, and I'd like to think most people wouldn't, but even if you're just about on board with him wanting to have one last, ahem, night of fun before his wedding:
(1) There's a time and place for that - it's not like he's getting with a stripper or dancer at his bachelor party. They're not on a wild weekend in Tijuana or Vegas.
What's more, they're in Miles' sanctuary, which, as Miles himself points out near the end, Jack has now ruined for him.
(2) By making his first night with Stefanie a double-date, it gets Miles directly involved in his deceit, and also means Miles has to live up (or down) to the lie that his book is being published. Plus Miles clearly isn't ready to date again, especially after Jack tactlessly broke the news about Victoria remarrying only a few hours earlier.
The tragedy for me is that Miles and Maya probably would have eventually gotten together anyway further down the line without Jack's interference.
(3) By Tuesday lunchtime, it's apparent that this isn't the one night stand he'd told Miles he was after. He's getting into a full blown relationship with Stefanie - spending all her free time with her, meeting her family, even bonding with her daughter, all while he's due to marry another woman just days later.
This is the point, for me, where everyone would say enough's enough. Even if he'd let things go that far, Miles should have left a note in the room for Jack and gone home on the Tuesday daytime while he and Stefanie were out for the day - by then of course he'd already had the (for him) disastrous double-date but cut your losses.
Things just snowballed from there. Miles was horribly used during that week - even on that last morning, if Cammy had turned out to be single, there's no telling when, or even if, Jack would have returned to the motel when it was the rehearsal dinner later on. Miles would have been sat there all day not knowing what was happening, if he needed to call Christine or her family to say they were running late etc.
Oh, and
(4), Jack announces that he wanted to have one last fling just 12 hours after he asked Miles if he thought he was doing the right thing getting married. That's a sign that if anything the wedding should have been called off, and again, it put Miles in a really difficult situation.
So yeah, original question - if you were Miles, when would you have put your foot down and told Jack to do one?