Personally this is my checklist when it comes to "should I have sex with this person or not?"
1. Both of you have consent from one another. This means both of you have the right to say no or yes whenever you want and have the right to not be pressured to do something you don't want. If one of you doesn't have consent, it is against the law and would be considered as sexual assault. Although females are often the victims of sexual assault, keep in mind that males can be victims too.
2. You both think that you are ready mentally and emotionally to have sex with EACH OTHER (seriously, this can change depending on the person you're planning on having sex with, even if you have had sex before with someone else). You can be emotionally and mentally ready or not even if you two aren't in a relationship so don't go around thinking that this isn't important just because you two aren't dating.
3. You two already have an idea on what may happen next (pretend nothing ever happened, just remain friends, develop into more, or what?) and have set ground rules on what you should do if whatever situation happens. Things happen and if one of you happen to develop feelings or something while the other one doesn't, you both have to know how to deal with this. In other words, you two need some sort of agreement that both will abide to. It doesn't have to be super formal and written down but it just has to be something that the two of you are aware of and can be on the same page.
So if you have these simple bases covered, then do as you please. That is simply all there is to it about my opinion on this matter. Oh, and if you do follow through, don't forget to use protection.
