The couple welcomed son Theodore into the world just two months ago but they are loving parenthood so much they're considering bringing their plans to have a sibling for their little boy forward.
Spencer said: ''We hope to have at least three, hopefully four kids.
''There was chat about having baby number two a few years after baby number one but we love baby number one so much that it may be sooner rather than later.''
The 30-year-old reality star feels ''blessed'' that Theodore is ''very well-behaved'' and revealed he's been sleeping through the night for several weeks.
In an interview with New! magazine, he said: ''[Fatherhood] is fantastic. Every time I speak about it, it only annoys people because everyone enjoys me suffering a bit. But there's no suffering whatsoever. We've been blessed with a very well-behaved child. I'm not quite sure where he gets it from. He sleeps like a dream, feeds like a dream ... We're honestly not tired. Theo has been sleeping through the night since he was five weeks old.''
But the former 'Made in Chelsea' star is expecting some ''meltdowns'' from the tot sometime soon.
He said: ''I've only heard him have a meltdown, like properly cry at the height of his lungs, twice in two months. Obviously he has a little whinge here and there but it is literally just whimpering. I think we're due a few more meltdowns.''
Spencer credits the tot's easy behaviour to the fact he and his 33-year-old wife have tried not to change their own lives too much and won't let their son ''take over''.
He said: ''Vogue and I are very relaxed parents and he's always with one of us. We haven't let him take over our lives.
''We're still busy, we still go to work. We're introducing him to an active lifestyle - he's been on a plane several times already. So far, so good.''