Persuading my bisexual partner for monogamy and offering anal intimacy in return

After a long day of classes, my horny girlfriend surprised me with a steamy anime sex session. But her suggestion for a threesome ignited a heated debate about our relationship's future. She expressed her desire for more sexual freedom, which I found unsettling. I've always been open about my own bi-curious nature, and the thought of sharing her with another man or she with another man didn't sit well with me. I proposed a compromise: if she agreed to remain monogamous, I'd be willing to take things to the next level and indulge in some assplay. She was taken aback by my offer, but intrigued. After some convincing, she agreed to the challenge. We headed back to her dorm, where things got wild. I teased her with some sexy lingerie before we engaged in a passionate anal encounter. The experience was intense and satisfying, leaving us both craving more.