spiritual or not, the pentagram is a positive symbol of protection. [unless in your religion it's frowned upon you can use your personal views on the symbol, but as someone who either doesn't care or is on a pagan path it would be a positive symbol] since you are inside the pentagram you could also interpret you're inside circle which is a holy space for many witches. white is also a positive sign, representing things like peace and new beginnings. [again, if you're from a culture that see's the colour white as negative go with that interpretation. dreams are personal, so you should try and interpret your own dreams]
the sex can also have several meanings, the sex itself could shadow your current sex drive or emotional state [say passionate sex vs soft caressing, the former you probably just want sex, the latter you want more love in your life] since this is an ex partner of sorts, coupled with the white, you could be scared about moving on. perhaps you have a change in your waking life [say a date, or have a crush on someone else] and you're nervous trying something new. your mind is showing you a safer past event.
overall i wouldn't worry too much about it, but try reflecting on your current life, this dream could be trying to comfort you because of some love related issues in your waking life.