Many WGs have partners, so I'm not at all fazed by that. Not really my business, anyway.
One WG I see for BDSM meets (she's a sub/painslut), said 'you should meet my husband, he'd like you'. So after a bit of thought, we met up in a dungeon for a MMF session after I'd corresponded with hubby by text. The couple had been on the swinging circuit for years.
So we had a memorable time subjecting WG to cane, crop, paddle and flogger. That was just for starters.
Even better, no money changed hands because it's against their principles to take cash in the course of swinging.
We've since repeated the scenario, more recently including a female friend of mine. I still see the married WG 'professionally', so to speak. She loves the money and she loves the sex; so it's 'win win' for her.