Sex is different with all partners. I refer to sex with someone new as being like a snowflake: no two partners are ever the same. Even if more than one partner does the exact same thing, the results won’t turn out the same. The context between you and each partner is different. Perhaps the physiological components are different as well, which can contribute to a unique sexual experience.
One big difference I am noticing right away is that you are considering marriage with this current partner. I am guessing that is something new, which suggests that he is unique to your previous partners. The way you feel about him, think about him, and see him in your life are all different. All of those differences affect the way you view him, and the two of you as a couple.
Sex with emotions and real intimacy takes on new context. You are, potentially, more involved on more levels. This can create anxiety for some, sexually speaking. I see women all the time who are not as comfortable sexually when there is added intimacy in the relationship. These women begin to fear how they are seen, what the man is experiencing, is it good, etc. The brain takes over and you miss the sex itself because you are too busy thinking about the sex in a disconnected way.
Try reconnecting to yourself and your physical sensations during sex play with your guy. I borrow from mindfulness practice when working with my clients around these issues. If you must be in your head during sex, then at least direct where your thoughts go and stay tuned in to what you are doing instead of observing. Pay close attention to how you experience everything you and your partner do during shared intimacy and see if that helps.
