Even a man like Dongfang Shuo has a girlfriend; she didn't see any problem with that. But a man who sleeps with a woman before marriage and still manages to come off as innocent and harmless, there was definitely a problem with that.
So after she had enlisted, she never talked about having a relationship with a man. Even when Dongfang Shuo sought her out later, she always claimed to be too busy. That's why she never dated Dongfang Shuo—a fact she never told Qin Xue. So Qin Xue always assumed that she never had the opportunity to be with Dongfang Shuo, when in fact, she just didn't want to.
Now she only considers having a one-night stand with Xiao Qi because she knows he doesn't have messy relationships with other women. Otherwise, she would've steered clear of him a long time ago. Of course, when she speaks of distance, she means emotional distance; she won't let anyone get too affectionate with her.