I mean, Mateo agrees, he is quite attractive. *wink* I'm sure she will see him around town a lot, because Teo is a very social creature, and just wants to be friends with everyone.
He would totally flirt back, because that's just how he is. Mateo would totally be down to be gym buddies. He has a feeling he's going to be hitting the gym a lot to deal with Emotions and Feelings. Or denying them. Maybe both?
Mateo's totally okay with you being shy, Will. He'll find something for you two to talk about, because that's what he does.