Is it normal to not want to mix friend groups?
Yep.Totally normal
Yes, it’s totally normal to prefer keeping different friend groups separate. You can enjoy each group on its own without turning every friendship into one big social circle.
Different friends may bring out different sides of you, or you may simply like the feel of each group as it is. Plenty of people keep work friends, old friends, hobby friends, and close friends in separate lanes—and that doesn’t mean you’re being secretive or disloyal.
Some people love a big blended group; others find mixing everyone tiring or awkward. You can say, “I’m keeping this one a smaller hangout,” without making it a whole thing. If groups happen to cross paths, you don’t have to play cruise director and make everyone bond.