5th house confusion

I have sun,mercury,rahu and venus all four in my 5th house. What does this mean? I am in college right now , never been in any relationship cuzI don't want to even I've got proposed by few ...but I have rejected all of them But this astrology thing seems very contrasting ...pls guide

My friend knows a bit about astrology . I showed him my kundli and he said that I will surely have extra-marital affairs in future.

I don't know ...does astrology guides all this irrespective of one's will?