In my experience this is never a good sign because inviting a friend for anything other than a threesome is code speech for "I don't plan on being intimate with you today but I still want your time and attention".
This is true even for a LTR - I might care who her friends are but I don't want them around more than necessary. They're her friends, not mine after all. Unless they're interesting people who might enrich my life, I simply see no point in hanging out with my girl and them at the same time. Less sex, more wasted time.
Problem is after a while girls catch up that I'm not interested in meeting their friends and the "If you care about me you must be friends with them too" talk begins and things go downward from there. They know what's up, that I'm trying to avoid their betaization process, though of course I can never overtly bring this up.
Soft-nexting seems overkill in this instance since technically she's not disrespecting me, so what's the best way to deal with it?