Often when played rol on internet, when the game allows sex it turns into an eternal non sense orgy, wich, for me, its lame when i´m after a rol game.
On the other side, i think a rol game should be as realistic as posible, and sex is part of reality, you can´t just cut it out without having something too artificial. I also think that the best games are those with less rules, each time you add as a rule something like "don´t do this" "don´t do that", "don´t have sex", part of the freedom in the game dies. So i would say i rather play rol where everything is allowed, and be carefull who i play with. I would only play with ppl who make it fun for me, as i always try to make it fun for everybody. If i´m willing to have a good game, i will run away from ppl that cannot control themselves.
And about the mood, i don´t think that´s a factor, it´s not your mood, but your char´s mood. Sometimes it´s hard to act acording to your char´s mood instead of yours, but that challenge make playing way more fun, and your experience of your own char more complete and realistic.

I like dress up for sex and play a role.

sex rp's are good and fun to paly but i personally think that they shouldnt be sex nonstop, give it some type of story line and it it will get better.

too right. a balance of story and sexual content is a must for me, but I can do either kind

Any good RP can be improved with adding sex to it.

Agreed. ;) Gotta prefer sex in my rps. Don't want it to always be the main focus, but it's definitely good to have.