Without singling anyone out, I'm a little offended about the judgmental attitude about "KICK THE KIDS OUT, THEY NEED TO GO". Sure, kids don't need to sleep with their parents, but there's a lot more involved behind it than just "medical reasons".
Love, comfort, nursing, security, etc. Both of my children were co-sleepers for a time. My first would end up in our bed more often than not because of nursing. She is 5, and sleeps in her own bed, but doesn't hesitate to come sleep with mom if she just wants some extra cuddles.
My 21 week old sleeps with me nearly every night. She's nursing, and she wakes up every 2-3 hours to eat. She wakes up, takes 15 minutes to eat, and another 30 minutes to go back to bed in her crib, during which time she also wakes up the 5 year old, who then takes another 15-20 minutes to get back to bed for herself. So every 2-3 hours, I'd be up for an hour. That cuts my 8 hours of sleep down to about 5, and when I'm cranky, everyone's cranky. When she sleeps with me, however, she doesn't even fully wake up to eat, she just nuzzles in, eats, and goes right back to sleep. Most of the time I don't even wake up more than to just adjust for her.
As for the dangers of co-sleeping, if it's done right it's safer than cribs, because parents and children both are aware of the other. It's called "protective arousal". My husband can tell you, when the baby adjusts, I adjust. When I roll over, even in my sleep, I will cuddle the baby and roll her over with me. We are always facing chest to chest. This is normal for co-sleeping, and as long as you don't have excessively heavy or fluffy pillows/blankets, and you don't ever EVEREVEREVER go to sleep under the influence of tobacco/drugs/alcohol/ Rx's, etc, there are -less- risks for SIDS with co-sleeping than with not. (Yes, tobacco).
All of this is very documented in medical journals/studies/with many Dr's, etc. Look around at other cultures, many of them co-sleep until the children are nearing puberty. It's been done this way for hundreds of years, and only recently did it became a huge problem - mainly in the 50's and 60's with an increase in SIDS because of parents putting their children down in fluffy cribs, face down.
Anyhow, I'm rambling. My point is, if you don't know the situation and haven't done the research, please don't just blindly judge or blanket assume. Everyone has different reasons for wanting to co-sleep, or to not co-sleep. Either way, it doesn't make it bad, as long as it's being done safely.
As for the initial question, we don't have sex with our kids in the bed. They do have their own beds, and will sleep in them. However, with my husband being deployed, I don't have to worry about the whole sex thing. If I want to get frisky with myself, she goes in the crib, mama does her thing, and then when she wakes up a few hours later for her feeding, if she needs to come back, she can.
As a side note, a lot of information can be found at Dr Sears' website, with a lot of external links to medical journals, etc.
I'm not trying to preach, but it's really no different to blanket judge a situation like this, as it is to say "all people who like BDSM were abused!", like many media outlets will tell you. Just my take.