There are some unwritten rules or shall I say unspoken rulesto the single life. These rules people expect you to just know or should just be aware by nature.
If its just sex, expect it to be just that and nothing else. We all need it (some more than others). So as a result, we take on partners. FWB (Friends with Benefits) can work out well but let's be honest. It wont be long before someone develops some sort of emtional attachment.