Hmmmm
I think the key thing for me in this situation would be how you met the guy?
Pp said she had exs who ended up friends who were in a fairly big mixed social group where everyone was kind of getting off with each other in a studentish way and that's cool.
What I find a bit weird is people who go online , and then are all "let's be friends " after about two meets?
I dated someone for about 2-3 weeks and we'd spent a couple nights together then it was like suggesting we stayed in touch and went to art exhibitions together 
It's not like I was terribly in love with him so that I was upset , or that I don't like going to exhibitions (joint interest) it's just a bit "potentially socially weird"? I mean we hardly knew each other that well.
It felt like he just wanted a harem of personable physically attractive women to do stuff with. Or access to my existing social group (Which cracks me up a bit because I don't really have one due to moving around a lot and working away).
It had Drama Llama mindset all over it. I mean after a certain age you value emotional and social equilibrium and peace more than "random people to do stuff with"
Not necessarily about keeping me on sexual standby but it's like "why not go to Meetup and do things with other men or women you AREN'T physically attracted to or mixed groups if you want friends ?"
It comes across as creepy and shallow and weird - "I want friends I have joint interests with who are also women I'm physically attracted to "
I mean I've been on OD , so obviously if I was pushy enough I could have a collection of "nice guy but I don't want a relationship with him for X reason " types as my "friends".
But those guys are out there to date and mate so I don't want to be having them hanging around and it all being socially awkward.