Just talk about it, tell your therapist what you are thinking...... because what you are thinking is likely a fantasy, rooted in the past. A good therapist will be able to help you work out what is triggering these fantasies, and therefore see them for what they are.... fantasies. Over time, realising they are fantasies will leave a space.... and into that space you can put some reality... a reality built from trusting your therapist is telling you what they feel and think.
Transference happens when you do not trust your intuition enough in the present, so you rely on past messages lurking in your subconscious. This means the way around transference is time and through time, trust.