Best way to know you're the side guy? Is delayed texting and erratic texting the biggest indicator? What else?

Anonymous
I've noticed that erratic and delayed texting from a girl can usually be a good indicator, where one day the girl will be texting you for hours on end within 5 minutes or less but other days it will take hours or even days for her to get back. Every time this has happened to me the girl already had a boyfriend.

anybody else have any other good signs?

some I've also noticed
- no mentions on social media, she'll never give out her real instagram or facebook
- you only hang out with her alone away from her friends or family
- you've never met her friends or family and never will
- she makes up stories about doing things with friends that usually don't make any sense
- lots of excuses
- she's never available last minute and has to plan everything way in advance
Best way to know you're the side guy? Is delayed texting and erratic texting the biggest indicator? What else?
2 Opinion