either in a naughty friendship or dating the woohoo will pop up eventually

Yes they would have to.

i've sent several "naughty friends" requests but no responses so far. im wondering, Phylistean, did the naughty friend have to accept the new relationship for the sneaky woo hoo to show up? thanks for the tip, by the way. i'm having same issue as Heidi.

I don't know if this will help, but I became naughty friends with a sims and was able to woohoo by clicking on the bed but nothing happen until it said sneaky woo hoo