Agreed with AT. Also wanna say I'd be creeped out if I felt like sex with his other partners was a requirement of dating him. It's fine to want it, but if it's a condition that's a little weird.
Me, 30ish bi female, been doing solo poly for roughly 5 years. Gia, Clay, and Pike, my partners. Davis, ex/friend/"it's complicated." Eric, Gia's husband. Bee, Gia and Eric's toddler.