<human>: We've been together about 3 months I'm 27 she's 33. We were recently talking about a friend of mine (20yrs old male) being clingy which brought up if he had other friends which I told her he didn't then she proceeded to ask if he had a girlfriend which I also told her he didn't because he doesn't. Then She immediately replied 'well he isn't bad looking so I don't know why he doesn't have one'. 

It kind of pissed me off and yes I can be jealous at times but I'm curious as to if anyone thinks it's reasonable for me to be irritated about her checking him out or if I'm just being childish. 

Keep in mind the day after she met him I told her how young he was and she said she couldn't tell because it was dark and she didn't get a good look at him. But now she saw him well enough to know he doesn't look bad.

 To me that's just like saying he looked good.

Can you give me the gist of the text in a nutshell?
<bot>: Should I be concerned that my girlfriend that is older than me finds my buddy who is 13 years younger than her attractive and is open about it?