Spike and Mac act pretty much the same around their crushes, both are young kids, both have crushes on adult women, both are mature for their ages and both are simps for them.

Mac is 8 and Frankie Foster is 22, so that's how I see the ages of Spike and Rarity. Not a real ship, but it's nice to know she actually cares for him.

Sidenote: Lauren Faust wrote a majority of Fosters Home for Imaginary Friends, so it's no wonder these relationships seem the same.