The 27-year-old's wedding will crown an exceptional few months for the Irish outside half, who signed off at Leinster with Amlin Challenge Cup and RaboDirect PRO12 winners' medals from two great finals at the RDS before helping the Lions make history.
Sexton will only get a short honeymoon before heading to Paris to launch his new career with Racing Metro, alongside fellow Lions heroes Jamie Roberts and Dan Lydiate. And if there is one thing the past six weeks on tour with the Lions has taught him it is the slender margin between success and failure.
"Today was the day that decided whether this was a massive success or a massive failure. Everything that had gone on before was irrelevant if we'd lost and it means everything now that we've won," said Sexton after the 41-16 third Test triumph at the ANZ Stadium in Sydney.
"It's an incredible place to be in there with the guys, even the guys that didn't tog out tonight, they're over the moon and celebrating just as much as the guys that were on the pitch.
"The big motivation as a player is you want to be remembered when you hang up your boots and you try to win as much as possible and do the right things as much as possible. Winning a Lions series is definitely part of that and we're in, I suppose, an elite group and it's a big privilege to be a part of that.
"The dressing room atmosphere was unique, just totally different to anything I've experienced. It's my first Lions tour so everything's been different and really special from that point of view.
"But that dressing room, it's a bit surreal because I suppose when they last won it, in 1997, I never thought I'd be in the next dressing room that won it. So it's a great place to be and obviously I'm very proud to be in there.
"I remember watching the 1997 tour in Ciss Madden's with the Bective crew and that's one of my first big rugby memories. That Lions DVD is a very special documentary and to be a part of something similar is really special.
"You're playing with guys you barely know and you have to forge that bond. I think you saw by the celebrations that we did that - we did the Lions tradition proud."
Sexton was an 11-year-old when Martin Johnson's side last grabbed glory for the Lions. Now he stands shoulder to shoulder with the likes of Gregor Townsend, Rob Andrew, Phil Bennett, Barry John and David Watkins as outside halves who have guided the Lions to a Test series victory.
Not only that, he popped up for the vital second half try that sparked a points avalanche that led the Lions to a record breaking win over the Wallabies in what was supposed to be a tense, nervous series decider.
"We were all fired up. Andy Farrell spoke brilliantly yesterday to the squad about having a different type of mentality, 'We're Lions and we have to be a step above what we expect at international level'. The lads really produced that tonight. Outstanding in defence, outstanding up front and we showed some glimpses in the backs of what we were doing in the warm-up games and got a couple of nice tries near the end."
"We were up for it last week and for the first Test, but we just played a bit better tonight. We got more set-piece and were more accurate, that's the bottom line," said Sexton.
"We wanted it as much as we did last week, but sometimes you can want it too much. We maybe wanted it a bit too much when we got to 15-9 last week and went into our shells a bit and wished the clock away.
"This time we grabbed it by the scruff of the neck and went for it and scored some tries. Rob Howley said before the first Test that if we scored two tries we'd win and he re-emphasised that point. We had Leigh with the boot keeping us ticking over. but we couldn't just rely on that.
"We talked about the 16 year wait a bit too much last week. We forgot about our performance and actually trying to do the things that we needed to do to win the game.
"We knew we weren't going to just be able to dog it out against a team like Australia with guys like Genia pulling the strings and the firepower that they have so we did a lot of homework last week on him and we managed to shut him down. He caused us some trouble at times, but we did a good job.
"It's been a brilliant experience being part of the Lions and for it to be a success is even more special. We'll celebrate hard for the next few days and the banter's great.
"I said to the lads, 'it's an unbelievable memory to make my first Welsh cap, one I'll remember forever.' It's good craic and that's why it's so special."
There will be one of the main attractions at another party at the end of the week to celebrate another major event, this time on home soil.
"Everything's been ticked so far this year. I wanted to finish the season on a high with Leinster and two trophies did that, and then there has been this success. Hopefully, I can stay out of trouble tonight and get home in one piece for the wedding on Friday," he added.