People are saying he should just compliment her. You're forgetting she's shown herself to be unpredictable as far as MC is concerned. He has no way of knowing that she actually wants a compliment from him and is not trying to trap him some way into complimenting him then accusing him of something.
Granted, on the outside looking in, being an omnipresent reader and all that, able to properly read her cues, if it is what the author intends, it appears she actually does want his compliment and she actually does want to get intimate with him. However, MC is plagued by the experience of dealing with her unpredictability which has led to his death in the past, or not reading her right and it leading to her his death in the past.