What a powerful, emotional bond you have. Sometimes it might even scare you how deeply you're connected and how intensely you feel for each other, and in fact, some very strange, strong and perhaps unwelcome feelings come up for your partner both in this relationship. How you deal with them is up to you, but taking the most positive route could be a matter of will, not chance.
Your sexual connection with this person is powerfully emotional and overwhelming; it could hold such a strong sway over them that they're irrationally jealous and possessive of you, even if they don't normally tend toward these feelings. They want to possess you, and they don't want you to pay attention to anyone but them. But that's not very fair, is it? After all, you both have plenty of relationships in your lives that are important to you -- ones that exist outside the romance you two share, and that came along before you two ever met. Why should you give those up or deny their importance just because you're with this person? Having more than one romantic affair at once is one thing that's definitely best avoided, but learning to allow you the space to maintain your friendships and other important relationships is an important lesson for both of you through the course of this affair.