The only kind of sex that has no serious consequences is masturbation. There's a difference between sexual desire and love. Sexual desire is a powerful physical excitement. Love is a powerful caring for someone else. It can also be physically exciting.
Love can exist without sexual desire, and sexual desire can exist without love.
Many people are happiest when both love and sexual desire are shared by both partners. Having sex with another person is very personal and very intimate. No matter how brief, sexual relationships are partnerships. Sex partners who understand this are honest and caring with one another. They have regard for one another's feelings and are willing to talk openly about their own.