With wife Jules due to give birth to their first child in March, Sebastian will embark on a 20-date national run in June, about the time the newborn is likely to discover his or her crying lungs.
"I'll be able to get out the house and Jules can juggle her time between the baby and the kitchen," Sebastian jokes.
But the Who's that Girl singer quickly admits he's can't wait to become a dad.
"No, really I'm looking forward to the crying because I'm the guy who gets excited by all the stupid stuff like cute little faces.
"All my friends say it happens so quickly and suddenly they're all grown up so it's tough going on the road when you've had your first baby.
"I don't want to miss out and come home to find the clothes we've bought don't fit any more."
Sebastian committed to the month-long tour to tie in with the release of his forthcoming album Armageddon, which is due out in May.
Baby Sebastian will quickly be introduced to the music world at a young age, as dad plans to have Jules and the three-month-old travel as part of his entourage, stopping in Adelaide to introduce the baby to its grandparents.
The former Australian Idol winner is already preparing to adjust priorities towards family life, starting by lowering the volume from his home studio.
Trips back and forth to his second home in Los Angeles are also likely to be minimised, with Sebastian wanting to prove himself as the devoted dad.
"I've got to play my part, you know, I can't have Jules doing everything and changing the nappies all the time.
"I'm hoping we'll have a super chilled baby because we're both programmed that way, so fingers crossed."
The follow up to 2010 album Twenty Ten is currently seeing Sebastian produce his trademark blend of pop and R&B under his own steam.
A shift away from co-writing with other musicians has enabled the space and time to work towards a more long-term project.
"All the albums I've enjoyed recently are ones that have taken a while to make," he explains.
"I look at artists like Adele and Gotye and their records were well worth the wait."
Sebastian admits he could pass the May deadline set by his record label but will work at a pace he sees fit, intent on creating something special.
"I've matured a lot in the way I view my music and the industry and my role in it.
"I know what I need to do and have a better idea of who I am as an artist."
Sebastian has also hardened up since discovering he is to become a dad.
His recent hit Don't Worry Be Happy was inspired by a fit of road rage launched his way, and while he prefers to write happy music he's "not that guy who thinks life is one big musical".
His anger was palpable after Kyle Sandilands tricked fellow X Factor judge Ronan Keating into revealing Jules's pregnancy days before their 12-week safety period.
"I was really angry at Kyle because people in our family have lost a child so we were very sensitive of that," Sebastian says.
"It was a dirty trick to play so I sent him some pretty abusive text messages."
* Guy Sebastian tours nationally from June 1 to July 1.