If that's the reason I wish it had been made more clear.
Why?
I thought it was pretty clear what her problem was when Odan was inhabiting Riker. She didn't just jump straight into the sack with him, it took a period of adjustment.
CRUSHER: Cerebral blood flow looks normal. I'll leave you a metabolic booster. Use it if the symptoms get worse.
RIKER: Beverly.
CRUSHER: Beyond that, I don't know what to do. This is all new to me.
RIKER: It is new to me as well. Please, don't go. We've got to talk about this.
CRUSHER: I don't know what to say.
RIKER: Nor do I, but I know that this silence will injure us.
CRUSHER: Well maybe you should have thought about that sooner. Maybe you should have told me what you were. It didn't seem to bother you to remain silent yesterday.
RIKER: It never occurred to me. This is what I am. Did you ever tell me that you are only a single being? Of course not. That was normal to you.
CRUSHER: I don't know who you are.
RIKER: You must understand, whoever I seem to be, I am Odan, who loved you. That has not changed. I still love you. I can't help that. If this causes you pain, I will suppress it, I will keep my distance. Doctor Beverly, I would never hurt you.
Then later in the episode...
CRUSHER: I'm giving you something that should help with the pain. At least for a little while.
RIKER: The pain's gone. Thank you.
(he takes her arm)
CRUSHER: Please don't.
RIKER: Please let me touch you, just for a moment.
(he leans in for a kiss)
CRUSHER: No. Please.
Then even later...
CRUSHER: Tomorrow's an important day. Do you feel ready for it?
RIKER: I'll be fine. I've been preparing.
CRUSHER: That's good.
RIKER: Yes.
CRUSHER: I'll check your vital signs in the morning before the representatives get here.
RIKER: I don't want them knowing I'm taking any medication.
CRUSHER: Maybe you could schedule a series of breaks.
RIKER: That's good.
CRUSHER: Yes.
RIKER: Beverly, I want you. If you're going to leave, you'd better go right now.
CRUSHER: I'm not leaving.
So there wasn't this instantaneous acceptance of Odan when he inhabited Rikers' body. After the first instance Crusher wasn't interested in watching Odan continue to play body hop-scotch over and over.