xW still hasn't met my GF and I haven't met her BF (I think they are still together) and it's been over a year. I don't think, personally, that you have to meet other person, unless you want to. But, as has been pointed out before, He might actually be a nice guy.
xW and I never had a timeframe on when we would introduce our new partners. I simply said "When I satisfied it is stable and long term". For me that ended up being 10 months.
The one thing rolling around my head if I were to meet him in the 'beginning stage' of them dating is to simply shake his hand at the end say 'Good luck'.
Married 9: Together 11 M:37 W:35 S:2 D:7 Bomb dropped 6/3/2017 W moved out 7/1/2017 Separation Filed: 8/1/2017 Modified to Divorce: 8/21/2017 Divorced: 10/5/2017