For me it's different if your having sex with someone you have an emotional involvement with. Kahit hindi pa kayo in-love sa isa't isa pero may connection na. Some say love can't begin with sex pero I'm not to certain about that. Iba kasi when you have an emotional connection with your partner kahit friend mo pa lang ito. Mas masarap.
You can allow both of yourselves to explore and suggest stuff to each other. I guess this is also why sex is so much better when you are close to that person and are very open with the lines of communication. If it's just having sex with no emotional ties involved parang kulang. Parang there's something lacking. Don't get me wrong, I've been through a one-night-stand here and there every so often pero iba talaga when it's with someone that you really like or even better if it's with someone you love.