Why does my best guy friend get jealous when I mention other guys?

[Anonymous]

Me and this guy dated a while back, but after things didn’t work out we agreed to stay friends as we get on really well. He’s now my best friend, and he’s said that he’d understand and be fine with it if I decided I wanted a boyfriend.

However, whenever I mention other guys, even as a joke, he acts as if he’s jealous. We’re close, and in ways we still act as if we’re dating, but we’re not exclusive, and he has referred to getting a girlfriend in the future.

What does his jealously mean?

[JohnAlaska43]

Simple guys do not like talking about guys with girls they are interested in.
Maybe he has feelings for you.
Maybe he is secretly in love with you.

[ZiZi_Bell]

He still likes you?
He wants to be exclusive. It's really that simple.

[LazyMan]

He probably likes you.

[Anonymous]

why do you think?