Am I allowed to be mad

So my best friend hooked up with a guy I use to have a thing for she was the one who told me I shouldn't be with him and I listened then she hooked up with him and I'm angry 
Am I allowed to feel this angry 

Glow Resources

Let’s Glow

Glow is here for you on your path to pregnancy

Glow helps you navigate your fertility journey with smart tools, personalized insights, and guidance from medical experts who understand what matters most.

25+ million

Users

4.8 stars

200k+ app ratings

20+

Medical advisors