OK, I think I got it:
You're not allowed to have sex with Steve's wife. He's married her because you're charging him too much to flash your tits at him.
Christian isnt getting married because he's a vampire and you're the slayer - you've totes got a buffy angel thing going on.. dear god i hope he doesn't sparkle.
You're not having sex with Riley because you're staking Steve... wait, Steve's a vampire too? And your boobies are how to kill them?

Also, darling 'and your hat' lady - clearly Riley doesn't want or need ravensword - why would he when he's got me? *grins*