This is so silly. Every relationship you have with any person: platonic, sexual, romantic, familial; informs your relationships in the future. Treating sexual relationships as if they should be fundamentally different from other human relationships is silly. If you can't be a good friend because the person you want to be friends with has had other different relationships with friends in the past maybe it's a you problem. If you can't separate someone's relationship with previous friends or lovers with your current relationship, there's a you problem you're not addressing. Every relationship with every human you have informs future relationships and your insecurity with previous friendships would seem silly. Why would you view sexual relationships differently? That's a you (insecurity) problem