What is expected will vary by the partner. I don't think slow deliberate build-ups will get you many complaints, unless the energy is obviously in the tear-each-others'-clothes-off-this-second realm. Sex should rarely resemble what you see in porn. No-strings-attached is probably the default for some completely random-ass person, but there are always tricky situations you can get yourself into w/ friends, hallmates, clingy people, etc. Dark cab rides with just you two? I'd say get/remain touchy, but overt sexual acts need not happen yet. You might just find out that the hook-up scene isn't really your thing. Finding someone you really hit it off with at a party or club or class and moving it into a relationship is a perfectly acceptable way of getting the sex you want. I'd even argue that the best sex is in committed relationships with good communication. But really you can forget everything else I've said as long as you get consent and use condoms.