I’m pretty sure my best friend has a thing for my boyfriend...

I’ve consulted with one of my other close friends too see if I’m just being crazy or jealous but she noticed it too...

The feeling she has a thing for him keeps growing stronger everyday... and I have no idea what to do about it because she’s told us in the past that if she ever did have a thing for him she wouldn’t tell us... so I feel like if I confront her about it she’ll deny it and get offended (since we had a little fight a couple of weeks ago I feel like it’s still little rocky and I don’t want any drama) but I wanna see if my boyfriend feels like she’s flirting with him or has noticed something and hasn’t said anything?

I completely trust my boyfriend and know he wouldn’t leave me for her, but after our fight I feel like she’s flirting with him in plain disregard for our friendship...

My questions are:

Should I tell him?

How do I tell him?

Should I confront her first?

Should I ask him first and then confront her?

Should I just try to ignore it entirely?