Sure. But be a grownup about it.
Dating someone isn’t the same as having a boyfriend or a girlfriend, and having a boyfriend/girlfriend isn’t the same as being in a committed relationship, a committed relationship isn’t the same as living with someone, and that isn’t the same as being married – though the further you get up that chain, the closer the definitions get and the blurrier the lines between the differences become.
What’s not acceptable is lying about it. If you’re a mature adult, be upfront that you’re seeing other people and give someone else their rightful option of not becoming involved with you.
Don’t lead someone to believe that they are the one and only if they aren’t. You’re within your rights not to be in a committed relationship, leading someone on isn’t a matter of masculinity or feminine power, it’s manipulative, immature, and reeks of no integrity.
Under no circumstances have unprotected sex: This means guarding against disease and pregnancy. It’s no one’s responsibility to protect you from getting sick or having a baby. If you’re a woman and he refuses to use a condom, cut your losses right there. If you’re a man, don’t rely on her birth control, bring back up. It’s a matter of self-respect and self-preservation. You may not know that person as well as you think and you don’t want anything left behind that someone else has to take care of. If your inclination is to have multiple partners, your obligation is to make that choice as safe as possible.