Laying on top of her naked body, her long legs are spread wide and my hard cock is resting on her pubic bone as we kiss.

Wouldn’t it be nice if I could just slip my cock inside you without having to bother with a condom?

Yes, it would, but we can’t do that!

I know, I’m just thinking out loud

But yes, it would be nice, condoms can be such a pain

But we both sleep with too many other partners for that to be realistic.

And that’s the best part of our relationship! We can say things like that and neither of us are offended!

She’s right, we can basically say “you’re a slut who has several other partners and my trust only goes so far”, and there are no hurt feelings.  Because safe sex and protecting our primary partners is that important and we both understand that.