My Best Friends fwb

So I was on a dating app and I found my best friends fwb (friend with benefits). I liked his profile just because I recognized him. Then he liked my profile back and messaged me. I told my best friend that he messaged me so I didn’t feel like I was hiding something. We’ve been talking for days and he’s interested in me. But he’s interested in having more to do with me. He said he isn’t opposed to a relationship with me. He even wants to hang out with me. He’s a great guy and he’s so funny. I feel bad because my friend is going to be upset with me if she knows him and I talk as much as we do and that he wants more to do with me.

UPDATE: I only talk to him because it’s a no strings attached situation between the two of them and they rarely ever see each other. He said he is more interested in me. The two of them barely talk and he feels a connection with me. I know it seems weird that they’ve been dirty together but I can get past that. She has also had sex with many guy so I feel like it isn’t as big of a deal.

UPDATE #2: My friend just got pregnant with another guy she hooked up with. I’ve been talking to her old fwb and he has only been talking to me. I feel like I’m in the safe zone.